a m18 sewerage mande works

8/18/2019 A M18 Sewerage MandE Works

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STANDARDSPECIFICATIONS FOR

CONSTRUCTION WORKS

2008

MMoodduullee – – 1188 – – SSeewweerraaggee MM&&EE WWoorrkkss


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Introduction

The Standard Specification is published in a series of 21 stand-alone modules each addressing

single distinct areas of the construction process. This stand-alone module 18 addresses the main

aspects of sewerage Mechanical and Electrical (M&E) works in general.

The purpose of the MoW STANDARD SPECIFICATIONS FOR CONSTRUCTION is to provide the

design professional with a guide for accepted construction practices for Ministry of Works projects.

As an aid to the designer, these Standard Specifications are provided for the inclusion in proposed

development projects for ease, efficiency and cost savings.

The Standard Specifications are not intended to limit the design responsibility of the design

professional. However, they establish a minimum acceptable criterion and/or quality for use within

Ministry of Works projects.

The design professional may increase the requirements of an item contained in the Standard

Specifications to meet job requirements, but when this is done, there should be no reference for

that item on the drawings to the Ministry of Works Standard Specifications and a new specification

should be included with the drawings or project contract documents.

The design professional must review all Standard Specifications to be sure that they are adequate

for the proposed project based on the job site conditions; the design professional is solely

responsible for the designs submitted under his seal.

In order to keep design standards current with changing regulations and improved construction

materials and practices this section will be updated and maintained by the concerned authorities of

the Ministry of Works. Prior to starting a new project, the design professional should contact the

concerned Directorate of the Ministry of Works to verify that he/she has the latest document

revisions.


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Module List

ModuleNo Module Title

1 Guidance and General Specifications

2 Concrete

3 Earthworks

4 Glass and Glazing

5 Joinery and Carpentry

6 Ironmongery

7 Internal Finishes including Thermal Insulation

8 Painting and Decorating (Internal & External)

9 Metalwork

10 Roofing

11 Structural Steel (and Coatings)

12 Structural Timber

13 Masonry

14 Plumbing and Sanitary

15 Mechanical Installation in Buildings

16 Electrical Installation

17 Sewerage Pipelines and Pipe work

18 Sewerage M&E Works

19 Roadworks

20 Landscaping

21 Dredging, Reclamation and Shoreline Protection


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Table of Contents

CLAUSE DESCRIPTION PAGE

Introduction 1

Module List 2

Table of Contents 3

Foreword 5

1. PART 1 GENERAL 6

1.1 Scope………………………………………………………………………………... 6 1.2 Extent of Contract………………………………………………………………….. 6 1.3 Standard Specifications…………………………………………………………… 6 1.4 The International System of Units (SI)…………………………………………… 6

1.5 Materials…………………………………………………………………………….. 6 1.6 Castings and Forgings…………………………………………………………….. 7 1.7 Lubrication………………………………………………………………………….. 8 1.8 Bolts, Screws, Nuts, Studs and Washers……………………………………….. 8 1.9 Noise and Vibration………………………………………………………………… 9 1.10 Notices and Labels………………………………………………………………… 9 1.11 Sub-Contractors and Suppliers………………………………………………….. 10 1.12 Delivery and Storage……………………………………………………………... 10 1.13 Documentation to be supplied by the Contractor……………………………… 12 1.14 Approval Procedures……………………………………………………………... 14 1.15 Shipping Documents……………………………………………………………… 14 1.16 Information Prior to Approval…………………………………………………….. 15 1.17 Installation…………………………………………………………………………. 15 1.18 Site Works…………………………………………………………………………. 16

1.19

Training…………………………………………………………………………….. 17

1.20 Nameplates and Data Labels……………………………………………………. 18 1.21 Spares……………………………………………………………………………… 18 1.22 Special Tools………………………………………………………………………. 18

2. PART 2 MECHANICAL EQUIPMENTS 19

2.1 Pumps……………………………………………………………………………… 19 2.2 Surge Vessels……………………………………………………………………... 30 2.3 Actuators…………………………………………………………………………… 31 2.4 Blowers…………………………………………………………………………….. 31 2.5 Air Conditioning and Ventilation Installations………………………………….. 32 2.6 Refrigeration Plant………………………………………………………………… 42 2.7 Ductwork, Grilles and Diffusers…………………………………………………. 56 2.8 Odour Treatment Technologies…………………………………………………. 61

2.9 Pipe Work Systems for Sewerage Works……………………………………… 66 2.10 Cast Iron Covers and Frames…………………………………………………… 73 2.11 Electric Overhead Travelling Crane…………………………………………….. 73

3. PART 3 ELECTRICAL EQUIPMENTS 79

3.1 Electric Motors and Ancillaries…………………………………………………... 79 3.2 Standby Generators………………………………………………………………. 80 3.3 Cabling……………………………………………………………………………... 84 3.4 Plant Earthing……………………………………………………………………… 87 3.5 Outdoor Equipment……………………………………………………………….. 89


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3.6 MCCs and Control Panels……………………………………………………….. 90

4. PART 4 CONTROL AND INSTRUMENTATION 112

4.1 Control Circuits and Equipment………………………………………………... 112 4.2 Instruments General…………………………………………………………….. 114 4.3 Level Instruments………………………………………………………………... 114 4.4 Flow Instruments………………………………………………………………… 117

4.5 Pressure Instruments…………………………………………………………… 121 4.6 Temperature Instruments………………………………………………………. 122 4.7 Analytical/Quality Instruments………………………………………………….. 122

5. PART 5 METHODOLOGY AND WORKMANSHIP 125

5.1 Workmanship…………………………………………………………………….. 125 5.2 Equipment Access and Maintainability………………………………………... 125 5.3 Fixing of Machinery……………………………………………………………… 126 5.4 Electrical………………………………………………………………………….. 127

6. PART 6 TESTING AND APPROVAL 128

6.1 Testing……………………………………………………………………………. 128 6.2 Submittals………………………………………………………………………… 129

6.3

Mechanical……………………………………………………………………….. 130

6.4 Electrical………………………………………………………………………….. 131 6.5 Commissioning…………………………………………………………………... 131

7. PART 7 REFERENCE STANDARDS 132

7.1 Mechanical……………………………………………………………………….. 132 7.2 Instrumentation,Control and Automation……………………………………… 134 7.3 Electrical………………………………………………………………………….. 136

Abbreviations 140


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Foreword

This specification provides the basis for Sewerage Mechanical and Electrical Works. It covers the

main requirements for all plant, labour, materials, transport, testing etc involved with the installation

of Mechanical and Electrical plant and equipments.

This specification must be read in its entirety, as it is structured in order of work-flow, which means

that items or activities appear in several places in the specification corresponding to the

progression of the construction process.

For larger or more complex or specialist projects, a project-specific Particular Specification for

Sewerage M&E Works may also be provided.

Absence of clauses for materials and methods does not necessarily signify that they can not be

used. Proposals for use of innovative methods and materials are encouraged and are subject to

review and approval by the Client.

Where the word ‘approved’ is used in this specification, this means that the Client or Engineer has

been consulted and has confirmed that the item or procedure is acceptable in the specific context

for which approval has been requested.


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1. PART 1 GENERAL

1.1 Scope

This module for Sewerage M&E works covers the general requirements for sewageMechanical and Electrical Installations at works. Requirements that are particular to theinstallation are given in the Particular Specifications. In the event that the Particular

Specification requirements conflict with these general requirements, then the ParticularSpecification requirements shall take precedence.

1.2 Extent of Contract

The Contractor shall provide everything necessary for the proper execution of the Worksaccording to the Contract, including any work, matter or requisite not particularlydescribed in these specifications that is required to meet the provision of the performancespecified.

The Contractor shall provide for the design, manufacture, delivery to Site, storage,erection, testing and take over procedures of the Mechanical and Electrical Plant andEquipment and documentation supplied through this Contract. The Contractor shall alsocarry out any specified ancillary civil works required.

1.3 Standard Specifications

The British Standard Specifications and International Electromechanical CommissionStandard quoted generally in this Specification are for guidance as to the quality ofmaterials, equipment and workmanship required. The Contractor may offer materials,equipment and workmanship to alternative National Standards Specifications and shallsatisfy the Engineer that the quality demanded by such specification is equal to or betterthan the appropriate British Standard Specification.

In all cases the quoted or appropriate British Standard or International ElectromechanicalCommission Specification shall be the latest edition with amendments made immediatelyprior to the date of submission of Tenders.

Where materials and equipment are specified to comply with British or other NationalStandards the Contractor shall, if required, obtain from the manufacturers and supply tothe Engineer's Representative the appropriate certificate of compliance with suchstandards.

1.4 The International System of Units (SI)

The International System of Units (System International d'Unites) of Weights andMeasures shall be used for all material and equipment.

1.5 Materials

Only materials and equipment that has a proven track record in the region will beaccepted by the Engineer for inclusion in the Works. Major items incorporated in theinstallation shall be manufactured according to the most well known standards andspecifications and of a type that has a proven usage history in different regions.

Equipment and materials to be provided by the Contractor and incorporated in the Worksshall be new, unused, and of the most recent, or current design and specification, andshall incorporate all recent improvements in design and materials unless detailedotherwise in this Specification. Materials shall be free from any flaws, defects orimperfections.


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Equipment catalogues, manufacturer’s specifications and detailed designs shall besubmitted for the examination and approval of the Engineer before any equipment is tobe ordered.

Equipment catalogues; manufacturer’s specification and detailed designs related to theproposed equipment shall be specific and shall include all information necessary for theEngineer to ascertain that the equipment complies with this Specification and the detailed

electrical & mechanical Specification and drawings. Data and sales catalogues of ageneral nature will not be accepted.

Items selected for the Works shall require low maintenance and provide a high level ofreliability.

Manufacturer's standard equipment shall be provided and as a minimum requirement,shall incorporate those features normally associated with the equipment as detailed inmanufacturer's specifications and literature, unless specifically excluded. Where this isnot possible, it shall be made clear at the Bid stage how and why the equipmentproposed differs from the manufacturer’s standard.

Unless otherwise specified, all items of Plant shall be rated for continuous service at thespecified duties under the prevailing atmospheric and operating conditions at site.

Equipment carrying out the same or similar functions shall be of the same size, type andmanufacture.

All component parts of the Plant shall be manufactured to a strict system of limits andcomplete interchange ability of similar parts is required.

Unless specified otherwise, heavy-duty long life materials and related components shallbe fitted to rotating equipment.

Submerged parts of the Works, shall be of non-corrodible material. Where this isimpractical appropriate treatment shall be applied to prevent corrosion. Equipment incontact with chemicals shall be resistant to corrosion or abrasion by those chemicals andmaintain their properties without deterioration by the passage of time, exposure to light orother cause.

Materials and components shall be stored in such a manner as to preserve their qualityand condition to the standards required by the Contract.

Materials and components shall be handled so as to avoid any damage or contaminationand in accordance with manufacturers' recommendations where applicable.

The use, installation, application or fixing of materials and components shall be inaccordance with applicable manufacturers' recommendations.

Where dissimilar metals would otherwise be in contact, insulation strips and/or sleevesshall be fitted as appropriate to prevent electro-chemical corrosion. Where stainless steelhas been referred to in this document it shall be provided to BS EN 10250: Part 4 Grade316L or equivalent grade.

1.6 Castings and Forgings

Only sound castings and forgings shall be incorporated in the Works. Welding, buildingup, filling or any other processes to recover castings will not be permitted in respect ofany casting associated with pumps, compressors, gear boxes or other such plant subjectto pressure or vibration.

Machined surfaces shall be free from blemishes and other surfaces shall be carefullyfettled to remove any foundry irregularities including fused-on sand.


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1.7 Lubrication

1.7.1. Bearings

Bearings shall be selected for adequate load bearing capacity and reliability.. They shallbe sealed for life or be fitted with automatic grease or oil lubricators. Lubrication pointsshall be grouped with a separate nipple and pipe feeding individual bearings. Lubrication

points shall be easily accessible. Bearings shall have a minimum design life of100,000 hours operation at maximum loading.

1.7.2. Gearboxes

Reduction gearboxes shall be robust and continuously rated and selected for reliabilityand efficiency over the required range of loadings.

Non-submersible gearbox drive casings shall be fitted with filling, level and drain points.Taps shall be fitted to the drain, and the gearbox shall be positioned such that the oil maybe collected in a suitable container.

1.7.3. Seals

Gearboxes shall have a life of 100,000 hours, be selected in accordance with A.G.M.A.recommendations for horsepower calculation and service factor application, and employa standard reduction ratio.

Except where particularly specified the Contractor shall select a seal, compatible with hisPlant and best suited for the worst conditions likely to be met when the Plant is inoperation.

Seal materials shall be compatible with and/or resistant to the fluid or gas being handled.

1.7.4. Glands

Glands shall be provided with renewable gland sleeves. Glands subject to abrasiveliquors or negative pressures shall embody suitably positioned lantern rings and a cleanwater continuous flushing system, operative whenever the Plant is in motion.

Gland adjustment nuts shall be readily accessible for routine maintenance.

Gland drain pipe work shall be installed, incorporating roding facilities and adequateinclines of 25 mm minimum diameter on water reclamation plant and 12.5 mm on watersupply plant, discharging to the nearest sump or drainage channel.

1.7.5. Lubricants

The Contractor shall tabulate all lubrication points, the recommended grease or oil, itsgrade and the recommended service interval in the form of a chart. The Contractor shallinclude the supply all necessary oils and lubricants for the initial fill and the first yearsoperation so that testing and commissioning may be carried out without undue delay.

1.8 Bolts, Screws, Nuts, Studs and Washers

Fixings to be used in conjunction with the works shall have thread forms which complywith BS 3643: Part 1 and Part 2 Isometric screw threads, and also BS 4190.

Exposed bolt heads and nuts shall be hexagonal and the length of bolts shall be suchthat, when fitted with a nut and washer and tightened down, the threaded portion shall atleast fill the nut and not protrude from the face thereof by less than two threads or morethan four threads.

Fasteners and fixings shall generally be manufactured from nickel-bearing stainless steel.


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Pipe work flange fixings shall be stainless steel.

Wood screws and fixings shall be of brass with round heads.

1.9 Noise and Vibration

With the envisaged maximum number of items of Plant running 'on-load' the soundpressure outside an envelope of 1 m radius from any item of Plant shall not exceed80 dB(A). Where the noise cannot be reduced to a level complying with this requirement,acoustic enclosures shall be provided. Where the Plant is installed in a separateroom/enclosure, the noise level shall not exceed 80 dB(A) outside the room/enclosure.Control room noise levels shall not exceed 55 dB(A).

Hazardous warning notices indicating that ear defenders are to be worn shall be installedat entrances to rooms/enclosures where the sound pressure level exceeds 80 dB(A).

Noise level measurement shall be made with a sound level meter which complies with BSEN 61672-2:2003 and which is fitted with an 'A' weighting network. The sound pressurelevel shall be measured in dB(A).

Machinery vibration shall not exceed the limits defined in BS 7854-1:1996, ISO 10816-1:1995.

Revolving parts shall be properly balanced both statically and dynamically so that inrunning up to, and at full normal speeds, and at any loads up to the maximum in eachcase, there shall be no undue vibration anywhere in the machine or in the Works orsurrounding neighbourhood.

The criteria adopted for vibration severity shall be the RMS value of the vibration velocityin millimetres per second.

Instruments for measuring vibration severity shall be in accordance with BS 4675: Part 2,ISO 2954 Mechanical vibration in rotating machinery. Requirements for instruments formeasuring vibration severity.

Limits of vibration severity for rotating electrical machines shall be in accordance with BSEN 60034: Part 14. This level shall not be exceeded when connected to the driven plantin the service position.

1.10 Notices and Labels

1.10.1. General

Wherever notices or labels are required the Contractor shall provide two labels. The firstshall be engraved with the text in English and fitted at prior to inspection at themanufacturer’s works. The second label shall be left blank for the Arabic text to be addedafter the equipment has been installed. The Engineer will provide the Contractor with theArabic translations and the Contractor shall engrave the labels and fix them to the

equipment in addition to the English labels

1.10.2. Notices

The Contractor shall provide and fix necessary instruction notices and schematicdiagrams adjacent to the various items of plant/plant system.

Equipment that may start automatically or may be started from a location remote from theequipment shall have a notice affixed. The notice shall bear the following legend in"WARNING THIS PLANT MAY START AUTOMATICALLY".


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Exits from the site, buildings and structures shall be indicated by notices, where these arewithin buildings they shall be illuminated.

1.10.3. Labels

Labelling shall include compulsory signs covered by British Standards BS 5499: Part 5and BS 5378: Part 2.

Each item of equipment shall be tagged with a unique tag number, the tag numbers willbe allocated by the Engineer following the submission by the Contractor of the equipmentlist for the Works.

Each item of equipment shall have a name and rating plate, engraved or stamped withthe Manufacturer's name, type and serial number of the equipment, details of the loadingand duty at which the item has been designed to operate and sufficient detail to allow theassembly to be readily identified in correspondence and when ordering spare parts.

Labels shall be robust, weatherproof and resistant to cracking and fracture. Colourfastnumbering and lettering, in block capitals and/or symbols shall not be less than 5 mmhigh. A label schedule shall be provided for equipment supplied. Labels shall include amaintenance reference number for the item of equipment to which they are fixed.

The Contractor shall furnish the Engineer with a schedule of labels as part of the detaileddesign information.

Labels shall, where practicable, be mechanically fixed to the equipment; the use of otherfixings shall be subject to specific written approval of the Engineer.

Outdoor labels are to receive 2 coats of lacquer.

1.10.4. Pipeline Identification

Pipes shall be colour banded in accordance with BS 1710 to identify their contents. Bandwidths may be reduced in agreement with the Engineer where space is at a premium.Bands may be applied using paint or approved plastic bands. Additionally, each pipe shallhave words describing its contents over each colour band.

1.11 Sub-Contractors and Suppliers

Any work carried out or equipment supplied by specialist firms, shall be approved by theEngineer. Installation Contractors shall be approved by the Engineer for the category ofwork to be undertaken.

The Contractor shall use manufacturers and suppliers as indicated on the drawing orwhere not indicated submit details of his proposed manufacturers, suppliers and/oragents for the approval of the Engineer.

1.12 Delivery and Storage

Plant agreed by the Engineer for delivery prior to erection shall be delivered to a positionagreed with the Engineer. Equipment not being immediately installed shall be stored onSite in a secure weatherproof temporary storage facility. The storage facility shall be tothe approval of the Engineer.

If for any reason the Employer delays the installation, the Contractor shall make provisionfor storage of his Plant and Equipment and shall not deliver to Site until the Engineer hascertified that the Site is ready to receive the equipment. In this case payment forextended storage beyond the programmed date for delivery shall be borne by theEmployer, and paid in accordance with the rates in the Schedule of Prices. These ratesshall include for refurbishment of goods in store to prevent deterioration and maintain a


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defects liability guarantee of 12 months from the issue of the Certificate of Completion ofthe Works.

Plant shall not be delivered to Site until all tests and inspections have been carried out tothe satisfaction of the Engineer. On approval of the test/inspections the Contractor shallapply to the Engineer for approval to ship. The request shall be in writing specificallyrelating to the plant to be shipped, and shall be submitted at least 14 days prior to the

shipping date.

1.12.1. Packing and Protection of Equipment

The Contractor shall be responsible for ensuring that items of equipment, special tools,spares, special lubricants, test equipment and documents are packed for transport and, ifnecessary, for storage in such a manner that protection against environmental conditions,mechanical damage and deterioration is effected.

All Plant shall be packed in accordance with BS 1133 in bundles or seaworthy containersor packing. No second hand timber shall be used.

All packing shall be suitable for the type of equipment involved and for transport fromfactories to the port of embarkation, sea/air freight, rough handling at the port ofdestination and movement to and on the Site.

Special provisions shall be made regarding the prevailing severe local climatic conditions.

All boxes, cases and/or bundles containing Plant shall be clearly marked on all sides.

The markings on the box, case and/or bundle shall be of block letters not less than50 mm in height, stencilled with black indelible paint. The following information shall beshown on each box, case and/or bundle:

CLIENT’S NAME AND ADDRESSCONTRACTOR'S NAMEPORT OF DESTINATIONCONSIGNMENT SERIAL NO.GROSS WEIGHT

NET WEIGHTSIZE OF BOX OR BUNDLE (LENGTH x WIDTH x HEIGHT)BRIEF INDICATION OF CONTENTSEQUIPMENT TAG NO.

The Contractor shall be entirely responsible for ensuring that the packing is suitable fortransit and shall be liable for any loss or damage due to faulty packing, having due regardfor the nature of the voyage.

1.12.2. Lifting Equipment

The Contractor shall be responsible for any lifting equipment necessary for off-loading,handling between storage and erection if necessary, and for the erection of his plant. TheContractor shall be responsible for satisfying himself as to the adequacy of Site roads

and hard standing necessary for lifting equipment requirements, and shall advise theEngineer at least 7 days in advance of the type, space and gross weight of any liftinggear or cranes.

The Contractor will be allowed use of the Employers permanent existing lifting equipmentif deemed suitable by the Contractor. The Contractor shall submit a lifting schedule andmethod statement to the Engineer for approval before using the permanent liftingequipment. On approval of the method statement, the Employer shall provide a Permit toWork for the lifting equipment.


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1.12.3. Receiving Damage Reports

The Contractor shall submit receiving reports to the Engineer to cover each individualshipment received and checked at the Site. Each shipment on arrival at the Site shall beunloaded, opened and carefully checked for any damage in transit and the Contractorshall immediately submit a damage report, countersigned by the Engineer, to theInsurance Company with copies to the Employer and to the Engineer. Where damage

has occurred in Marine Transportation a copy of the damage report shall also be sent tothe registered/appointed surveyor.

In all cases of irreparable damages, the Contractor shall immediately notify the relevantmanufacturer(s). He shall also immediately notify the Engineer of the actions he will beinitiating and undertaking in order to repair or replace the damaged part(s) and of theconsequences this damage will have on the completion date of the Works. Any repairsproposed by the Contractor will be subject to the approval of the Engineer.

1.13 Documentation to be supplied by the Contractor

1.13.1. General Requirements

Documentation shall be submitted in English.

Documentation shall be supplied in both paper and electronic versions in the quantitiesdetailed below. The format of the electronic copies shall be agreed with the Engineer.

Documents submitted for approval shall be signed as approved by the Contractor. In thecase of sub-contractor documents, these shall also be checked by the Contractor prior toissue for approval. The Contractor shall date stamp, and sign each of the sub-contractor'sdocuments. Any documents submitted to the Engineer for approval that have not beensigned as checked and approved by the Contractor wil l be returned for re-submission.

Submissions by the Contractor shall be accompanied by detail of any proposeddeviations from the requirements of the Contract, or failing which it shall be deemed thatthe Contractor’s proposal are fully compliant vide the requirements of the Contract.

1.13.2. Drawings

Four copies of the following drawings shall be submitted for approval within the periodstated from the date of the Order to Commence or other date thereafter as directed bythe Engineer:

Details of electrical circuits and components.

Schematic diagrams complete with a legend of symbols used. The diagrams shallincorporate a grid system for relay contact identification.

For PLC systems a fully annotated version of the PLC programme software shall besupplied in both paper and electronic format.

Instrumentation schedules and loop diagrams.

Cable schedules and cable route drawings; including cable sizing calculations inaccordance with BS 7671 Requirements for electrical installations, IEE WiringRegulations - Seventeenth edition

Draft Plant and valve schedules including Employers plant numbers. This schedule shallbe updated monthly until all Plant has been approved. A final version shall be included inthe Operation and Maintenance manuals.

Additional drawings of particular items: if called for by the Engineer.


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Dimensions of cubicle support plinth including loading.

1.13.3. Testing and Commissioning Documentation

The Contractor shall produce documents which fully describe and detail tests to beundertaken on the Works and shall include but not be limited to the following:

• Manufacturing and type test certificates.• Factory Inspection programmes.

• Inspection procedures.

• Test reports.• Commissioning Programme.

• Commissioning procedures and records.

• Dry (and clean water) test procedures and method statements, identifying approvalrequired, i.e. permits to impinge.

• Taking Over test procedures and method statements identifying approvals required,that is, permits to impinge.

• Records of plant maintenance and plant failures prior to take-over.

Documents detailing test programmes or procedures shall be submitted to the Engineerfor approval 2 weeks prior to the testing or commissioning taking place. A complete

record of the testing and commissioning procedures and results shall be included in theO & M manuals.

1.13.4. O&M Manuals

No later than 2 weeks before plant is offered up for Tests before Completion 3 copies ofthe draft instructions for the Operation, Maintenance and Overhaul of the plant shall besubmitted for approval by the Engineer.

The Contractor shall provide the Employer with three copies of approved instructions foroperation, maintenance and overhaul of the equipment, including drawings of the internaldetails referenced to enable any spare parts to be readily ordered. Instructions shall bebound together in durable, hard backed, plastic covered binders or folders.

The instructions shall comply with BS 4884: Parts 1-3.

Equipment not supplied under the Contract shall not be referred to in the instructionsexcept where the operation control and instrumentation of equipment requires existingequipment to be incorporated.

The instructions shall include but not be limited to the following:

• Recommendation for consumable supplies, for example, pump spare parts for twoyear operation.

• A brief outline of the operation of the Plant including the sequence of events requiredfor the operation of each item of Plant. The information shall be in sufficient detail toallow uninstructed personnel to be instructed in the operation of the Works.

• Instructions on how to stop and start the Plant, noting any safety and operating

sequence requirements.• Details of required preventive maintenance with recommended frequencies of action

including the testing, adjustment, and calibration of equipment followingmaintenance and during normal operation.

• Details of each item of equipment including the name and address of themanufacturer and the local agent, type and model, serial number, duty and rating,clearances and tolerances where applicable.

• Spare parts lists containing all necessary information for ordering parts.

• Lists of packing seals and gasket materials.

• List of special tools required for maintenance.


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1.14 Approval Procedures

Approval will be given by the Engineer within twenty-one days of receipt of the drawingsor documents. The Engineer will inform the Contractor by returning a copy of thedocument, or alternatively the status may be confirmed by letter without returning a copyof the document, marked with one of the following remarks:

• "Approved"• "Approved Subject to Comments"

• "Returned with Comments"

• "Examination Not Required"

The remark "Approved Subject to Comments" authorises the Contractor to proceed withthe fabrication subject to the corrections or comments noted on the document and/oraccompanying letter or approval sheet.

After correction, the document shall be resubmitted to the Engineer for approval with allcorrections made on the drawing.

The remark "Returned with Comments" indicates that the document must be revised andresubmitted for approval before proceeding with the manufacture.

The remark "Examination Not Required" indicates that the details on the document arenot considered to require approval by the Engineer due to such details being standard,typical etc., or not relevant to the acceptability of the equipment/design.

The approval shall not be taken as constituting an expression of opinion on the part of theEngineer as to the strength or efficiency of the plant and equipment or to its correctnessor in any way relieving the Contractor from his responsibilities or obligations under theContract.

1.15 Shipping Documents

The Contractor shall submit complete shipping documents as soon as possible aftershipping, in order to reach the Engineer before the arrival of the ship. Responsibility for

delays, loss or damage to shipping documents shall rest with the Contractor. Theshipping documents shall be distributed as shown in Table 1:

Table 1 – Document Distribution

Documents Employer Engineer’s Site Office

Original 1 -Shipping Invoice forthe Consignments Copy 1 1

Packing List 1 1

Original 1 -Bill of Lading

Copy 1 1

Original 1 -Certification of Origin

Copy 1 1

Original 1 -Manufacturer’sCertificate Copy 1 1

Confirmation of Declaration of Insurance 1 1

Certificate of Inspection Authority 1 1

Should the Work or any part thereof, the manufacture and/or supply of any material,equipment or plant component as well as any equipment or tool required for the Work bedelayed with respect to the relevant time schedules, the Contractor shall transport thepart or component delayed by air at no extra cost to the Employer.


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1.16 Information Prior to Approval

The Certificate of Completion shall be processed upon the completion of the following.

• Dry test

• Wet Test

• Submission of O&M Manuals

• Submission of As Built or As Installed Drawings

Certificates of Completion of the Works will only be issued by the Engineer upon hisreceipt and approval of the following:

Three copies of approved Instructions for the Operation, Maintenance and Overhaul ofthe plant installed, specifically written for this particular installation.

Four copies of recommendations for consumable supplies, fro example, packing andlubricants for the plant installed. This shall include a summary routine maintenance chartcovering all plant supplied.

The information contained in the manuals shall be correct for the installation at the time ofissue. The Contractor shall supply up-dated information for incorporation in these

manuals.

Information during Period of Maintenance:

After installation of the plant has been completed the Contractor shall supply three copiesof the following associated `AS INSTALLED' drawings and documentation for approvalwithin 6 weeks of the issue of any Certificate of Completion of the Works.

General arrangement drawing showing all equipments, switch gears, motor controlcentres, control panels, cabling and pipe work.

Detailed arrangements of any conduit work buried in floors, walls or ceilings, in anystructure.

Schematic electrical circuit diagrams.

Any modification or corrections undertaken during the commissioning affecting theoperating and maintenance instructions.

Within 12 weeks of the issue of any Certificate of Completion of the Works the Contractorshall provide and forward to the Engineer two complete sets of associated reproducibledrawing negatives of final 'As Installed' drawings of the Works. Lines and lettering ondrawings shall be of a consistent black colour suitable for reduction to 35 mm negativemicrofilm.

1.17 Installation

1.17.1. Setting Out and Fixing

The Contractor shall be responsible for accurately aligning, setting and fixing in positionequipment supplied by him, including drilling holes required for expanding bolts and theprovision and placement of bolts, holding down bolts, grout and so on.

1.17.2. Plinths and Grouting

The Contractor shall provide all supports (excluding reinforced concrete piers/plinths),anchors, grouting and fixings necessary for the installation of his plant unless indicatedotherwise on the drawings.


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The Contractor shall apply a concrete protective coating to all grouting works, whichgenerally is to be as per the surrounding concrete works.

1.17.3. Position of Equipment

The exact position of equipment supplied under this Contract shall be agreed on Site bythe Engineer.

1.17.4. Contract Drawings Details

The position of structures shown on the Drawings shall be deemed to be correct for thepurpose of costing the Contract. The Contractor shall check dimensions prior tosubmitting his drawings for approval. Any conflict between the Drawings and measureddimensions shall be brought to the attention of the Engineer.

1.18 Site Works

1.18.1. Erection

The Contractor shall be responsible for all aspects of erection to provide a completeworking installation.

1.18.2. Take Over Procedure

Take over Procedures shall be carried out in three stages; visual inspection; tests beforecompletion of the Works; setting to work and trial operation.

1.18.2.1 Visual Inspection

Visual inspection of the Works shall be carried out, after the Contractor has notified theEngineer of substantial completion of installation of the Works, by the Engineer and theContractor who shall produce a list of outstanding Works to be completed prior to theissue of the Certificate of Completion of the Works. The Engineer may permit certainminor items to be effected during the Period of Maintenance providing they do not affectthe safe and satisfactory operation of the Works.

1.18.2.2 Tests before Completion

The Contractor shall agree a programme for carrying out tests before completion at anagreed time and date. A detailed schedule of tests before completion shall be producedand agreed with the Engineer, highlighting each test to be carried out. Space shall beallowed in the schedule of tests for the Engineer and the Contractor to sign and dateeach item of the schedule. The schedule of tests shall include a breakdown of systems,equipment, instrument and device installed in the Works with each light, alarm lamp,control function and circuit being included to enable them to be 'signed off' when theyhave been demonstrated as operating in compliance with the Specification.

The Contractor shall carry out tests before completion prior setting the Plant to work.

Tests before completion shall include all equipments, instruments and devices installed.

Pumps: The Contractor shall demonstrate the operation of pumps, over the entire rangeof operating levels in the sump, to show that pump run out, cavitations, a closed valvecondition, motor overload or other failure does not occur. The Contractor shall undertakeflow tests using the Contract flow meters and calibrated pressure gauges to determinethe ability of the system to deliver the required flow.

Pipe work: The Contractor shall carry out pressure tests on individual lengths of pipework to at least 1.5 times the maximum working pressure, including surge. Air pipe work


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shall be tested hydraulically, before a repeat test on air is carried out at normal operatingpressures and pipe joints tested for leaks.

Motor Control Centres: The Contractor shall carry out complete function tests ofsequence and automatic control circuits including fault conditions, safety interlocks andtelemetry signals. Function testing shall be as far as is practicable carried out by thesimulation of remote instrumentation and controls at their mounting position.

Instrumentation: The Contractor shall carry out calibration and proving tests. Whereinstrumentation drives recorders or controls process Plant, simulation of operatingconditions shall be carried out to demonstrate the correct functioning of the recorders orprocess Plant.

Electrical and Earthing Systems: The Contractor shall carry out tests in compliance withthe Wiring Regulations of the Institution of Electrical Engineers

Other M & E Items: The Contractor shall carry out a mechanical and electrical inspection,and full operational tests on each item.

Lifting equipment: The Contractor shall ensure that all items of lifting equipment aretested on site by an independent inspector and a Test Certificate issued.

The Contractor shall provide three copies of test certificates for each item of Plant, andinclude the same within the Operation and Maintenance manuals.

1.18.2.3 Setting to Work

On satisfactory conclusion of the tests before completion the Contractor shall set thePlant to work and test it to demonstrate its ability to comply with the Contract.

For plants which use chemicals, the optimisation of the use of chemicals means settingthe Plant to Work at minimum chemical cost to achieve the Specified Performance.

Full functional testing of the Plant under working conditions shall be undertaken.Following completion of the demonstration the Contractor shall submit certificates for theEngineer's signature to confirm satisfactory performance.

1.18.3. Electricity Supply Company Tests

Where a connection is required by the “Electricity Distribution Directorate of theElectricity and Water Authority” at the Site, the Contractor shall be responsible for servinga completion of installation advice, together with an inspection certificate, kWh metercalibration, to the Electricity and Water Authority for the whole of the installation.

A copy of the inspection certificate shall be displayed at the installation, and a copyincluded in the Operation and Maintenance Manual.

1.19 Training

During the setting to work period, the Supplier shall, using the approved instructions foroperation, maintenance and overhaul, train the Client staff in the safe and efficientoperation of the Works. A Certificate of Completion will not be issued without the trainingbeing completed to the satisfaction of the Client.

Instruction of the SEOMD staff shall be divided into two categories: Operation andMaintenance. The syllabus of the instruction for each category of staff shall be suited totheir particular needs and agreed in advance with the Engineer.

The programme of instruction shall be agreed with the Engineer at least two weeksbefore the commencement of the instruction.


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Training shall be carried out by suitably qualified personnel approved in advance by theEngineer. The Contractor’s training instructors shall provide the training periods asdetailed in the Scope of Works.

Instruction of the different categories of staff may proceed concurrently, providing thatseparate instruction is provided for each category.

One man-day shall be defined as an eight hour working day at the Works. Travelling timeshall not form part of this period. Allowance shall be made for varying instruction timesfrom day to day to take into account shift working by the operations staff.

The purpose of the instructions shall be to familiarise the operations staff with all aspectsof the Works and provide detailed instruction of the operation and maintenance of theparticular mechanical and electrical equipment supplied under the contract, as relevant tothe category of personnel. The operations staff can be assumed to be experienced intheir respective trades in general, but not necessarily on any particular equipmentprovided as part of the Works.

1.20 Nameplates and Data Labels

Pumps, motors, gearboxes, control panels and similar items of equipment shall be fitted

with cast bronze or stainless steel engraved nameplates, giving relevant information, e.gModel, Type, Rating, Speed, Electrical Information, and Bearing Details. Nameplates withdata embossed on by punching or etching are not acceptable

Items supplied with rating plates in an inaccessible position (for example, submersiblepumps) shall have an additional identical rating plate provided as a loose item with a non-conducting cord or string suitable for hanging within the control panel.

All items of equipment shall be provided with a unique identification number to a systemto be advised by the Engineer. The Contractor shall provide a schedule of plant includingidentification numbers.

1.21 Spares

Wherever possible there should be a local dealer or Agent within the Kingdom of Bahrainfor imported equipment.

Within three months of the issue of the Order to Commence the Works, the Contractorshall issue the Engineer priced list recommended spares for one and five years ofoperation of the Works. The prices advised shall remain valid for any spares orderedbefore the issue of the Certificate of Completion of the Works.

During the 'Period of Maintenance' the Contractor may be permitted to use any spare partprovided pursuant to this Clause in order to rectify any defect. If however the defect isattributable to the Contractor, any spare part so provided is to be expeditiously replacedby the Contractor.

On the basis that the Employer's spares requirements for the Period of Maintenance are

advised within three months of the receipt of details by the Engineer, the provision of thesaid spares shall represent a pre-requisite of the issue of any Certificate of Completion ofthe Works.

1.22 Special Tools

The Contractor shall provide one set of any new and unused special tools not obtainablefrom local retail outlets for the maintenance of Works. They shall be contained in clearlylabelled boxes with hasp and staple suitable for padlocking.


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Components likely to become worn in the course of normal operation shall be capable ofbeing easily replaced making use of readily exchangeable components. Lowmaintenance costs, reliability and trouble-free operation shall be prime considerationswhen selecting pump units.

Pump units shall be provided from within manufacturer's standard range which shall meetthe quantity/head duty requirements within the high efficiency band of the pump

characteristics. The pump curve shall have non-overloading power characteristics unlessagreed otherwise by the Engineer.

Pump units shall be quiet in operation, free from vibration and the shaft speed shall notexceed 1,500 rpm.

All rotating parts shall be statically balanced during manufacture and dynamicallybalanced after assembly.

2.1.2.2 Pump Volute Casing

The pump casings shall be of close grained cast iron to BS EN 1561 free from blowholesand other imperfections.

Casings shall be manufactured and pressure tested in accordance with BS EN ISO 9906.

The pump casing shall be fitted with renewable suction wear rings.

Access shall be provided in the pump casings in the form of large hand holes, forinspection and cleaning of the pump interior.

Pump casings shall be provided with a drainage cock at the bottom of the lower casingsection and an automatic air release valve and cock on the top of the volute casingsection. The discharge from fittings shall be piped to the station drainage system. Smallbore pipes shall be heavy grade copper tubing.

2.1.2.3 Impellers

The impellers shall be cast in one piece from close grained cast iron to BS EN 1561. Theworking faces shall be accurately machined and finished smooth with each impeller beingbalanced statically and dynamically to ensure smooth running.

The impellers shall be of the single bladed open or spiral vane type or two port singleentry choke resistant type. Where the two port entry type is utilised the vanes shall besupported on both sides of their entire length by the outer shroud. The impellers shallhave auxiliary vanes on the outside of the shrouds to minimise the recirculation of theliquid within the pump casing and to reduce the pressure around the shaft seal.

The impellers shall be securely keyed and locked to the pump shaft.

The impeller diameter shall be machined to comply with the required duties andmaximum efficiencies.

2.1.2.4 Fittings

Each pump shall be fitted with the following fittings as standard requirements:-

• A combined automatic air release and syphon breaker valve shall be fitted into thepump delivery pipe work;

• 25 mm bore gland drainage pipe from the invert of the sill on the top gland cover andleading down to discharge into the dry well drainage channel to preventcontamination of the pump casing or walkways.


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2.1.2.5 Shafts and Sleeves

The pump shafts shall be constructed from high tensile alloy steel and shall be fitted witha hardened steel sleeve extending through the full length of the shaft seal.

Transmission shall utilise universal joints and a splined slip joint at the pump connection.Universal joints shall have needle roller bearings. The weight of the transmission shafting

shall be carried by a thrust bearing in the motor stool. The splined shaft shall ensure thatno load is transferred to the pump from the shafting. Normal shaft running speed shall bewell below the first critical speed. The Contractor shall submit his calculations to confirmthis.

2.1.2.6 Glands

Pumps shall be supplied with soft packed glands.

2.1.2.7 Drive Coupling

A suitably sized rubber bushed flexible coupling shall be fitted between each pump anddriving motor. The coupling shall be fixed to the pump and motor shafts using keys andkeyways.

2.1.2.8 Pump Motor

The motor speed shall not exceed 1,500 rpm.

2.1.2.9 Temperature Transducer Pockets

The pump Non-Drive End bearings and the pump Drive End bearings shall be fitted withtemperature pockets for the reception of resistance thermometer probes.

2.1.2.10 Pressure Gauge Tappings

Each pump set shall be provided with both delivery and suction gauge tappings such thatwhen fitted they are in an upright position. Each tapping shall be isolated with a gun-

metal gauge cock.

2.1.2.11 Pressure Gauges

A pressure gauge shall be provided and installed at the above suction and deliverytappings. The gauges shall be of the diaphragm operated sewage installation type.

2.1.2.12 Guarding

The Contractor shall include for guards to completely enclose the moving parts of plant.

2.1.2.13 Engraved Nameplates

Each pump shall be provided with engraved nameplates as follows:

• Duty Plate: Indicating the type, impeller diameter, and output at normal duty, normalduty head, speed, serial number and pump curve number.

• Identification: Corresponding with the pump control panel designation, for example,'Pump No 1'. The characters shall not be less than 30 mm high.

2.1.3 Split Case Centrifugal Pumps

2.1.3.1 General

Pump units shall be designed to handle the process fluid and for continuous operation.The pumps shall be electric motor driven.


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Pump and motor units shall be continuously rated. Components likely to become worn inthe course of normal operation shall be capable of being easily replaced making use ofreadily exchangeable components. Low maintenance costs, reliability and trouble-freeoperation shall be prime considerations when selecting pump units.

Pump units shall be provided from within manufacturer's standard range which shall meetthe quantity/head duty requirements within the high efficiency band of the pump

characteristics. The pump curve shall have non-overloading power characteristics unlessagreed otherwise by the Engineer.

The pump and its driving motor shall be separate machines, open coupled, using aflexible coupling to form an integral unit mounted on a suitable common rigid base plateor base frame. A flywheel may also be incorporated in the drive train if required for surgesuppression. Each component shall be dowelled to facilitate re-assembly.

Pump units shall be quiet in operation, free from vibration and the shaft speed shall notexceed 1,500 rpm.

All rotating parts shall be statically balanced during manufacture and dynamicallybalanced after assembly. The rotating parts shall be supported in substantial bearings ofapproved design.

2.1.3.2 Pump Volute Casing

The pump casings shall be of close grained cast iron to BS EN 1561 free from blowholesand other imperfections.

Casings shall be manufactured and pressure tested in accordance with BS EN ISO 9906.

The casing shall comprise of two sections, split to provide complete access to theimpeller and other rotating parts without disturbing the pipe work connections.

The sections of casing shall be secured together using substantial stainless steel studsand nuts. To ensure accurate re-alignment of the casing section stainless steel dowelsshall also be fitted.

To facilitate the dismantling of the casing halves equally spaced tapped holes shall beprovided in one casing flange to allow jacking bolts to separate the joint.

Renewable suction wear rings and interstage bushes manufactured from zinc freebronze, or LG4 Bronze to BS EN 1982 shall be provided.

Each pump shall be fitted with a drainage cock at the bottom of the lower casing sectionand an automatic air release valve and cock on the top of the upper casing section. Thedischarge from each of these fittings shall be piped to the station drainage system via atundish. Small bore pipes shall be galvanised mild steel.

2.1.3.3 Impellers

Impellers shall be manufactured from zinc free bronze, or LG4 Bronze to BS EN 1982,

keyed to the shaft and securely locked in position, the whole assembly being bothstatically and dynamically balanced. Impeller surfaces shall be machine finished free fromblowholes and imperfections.

The impeller diameter shall be machined to comply with the required duties andmaximum efficiencies.

2.1.3.4 Shafts and Sleeves

Shafts shall be of mild steel protected with renewable stainless steel sleeves, where theypass through any wear inducing sealing arrangement.


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2.1.3.5 Bearings

Bearings shall have a design life of 100,000 hours.

2.1.3.6 Glands

Split case pump units shall be supplied with soft packed glands.

2.1.3.7 Drive Coupling

A suitably sized rubber bushed flexible coupling shall be fitted between each pump anddriving motor. The coupling shall be fixed to the pump and motor shafts using keys andkeyways.

2.1.3.8 Pump Motor

The motor shall be sized to allow for the provision of flywheels for surge suppression asnecessary.

2.1.3.9 Temperature Transducer Pockets

The pump non-drive end bearings and the pump drive end bearings shall be fitted withtemperature pockets for the reception of resistance thermometer probes.

2.1.4 End Suction Centrifugal Pumps

2.1.4.1 General

Pump units shall be designed to handle final effluent and continuous operation. Pumpsshall be Electric motor driven.

Pump units and motors shall be continuously rated. Components likely to become worn inthe course of normal operation shall be capable of being easily replaced making use ofreadily exchangeable components. Low maintenance costs, reliability and trouble-freeoperation shall be prime considerations when selecting pump units.

Pump units shall be provided from within manufacturer's standard range which shall meetthe quantity/head duty requirements within the high efficiency band of the pumpcharacteristics. The pump curve shall have non-overloading power characteristics unlessagreed otherwise by the Engineer.

Tapped holes or other provisions shall be made in the main casting and impeller of thepump for the insertion of jacking screws or fixing other such drawing gear necessary tofacilitate the dismantling of the pump.

2.1.4.2 Pump Casing

The pump casing shall be of close grained cast iron to BS EN 1561 grade 14, free fromblowholes and other imperfections, suitable for use with final effluent.

2.1.4.3 Mechanical Seals

Pumps shall be fitted with a mechanical seal with both the rotating and stationary facesbeing tungsten carbide or other approved materials. The pump mechanical seal designshould he such that prolonged periods of dry running do not affect the pump ormechanical seal.

2.1.4.4 Pump Motor

The motor speed shall not exceed 1,500 rpm.


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2.1.5 Submersible Pumps

Pump casings shall be manufactured from close-grained cast iron in accordance with BSEN 1561 or as defined in the particular specification. An oil filled casing shall separate theelectric motor from the centrifugal pump.

Mechanical seals shall be fitted to the pump shafts which shall prevent water from

entering the oil casing and oil from entering the motor casing. A moisture detectionsystem shall be provided in the motor stator casing, wired to initiate an external alarm.

Pump units shall be provided from within manufacturer's standard range which shall meetthe quantity/head duty requirements within the high efficiency band of the pumpcharacteristics. The pump curve shall have non-overloading power characteristics unlessagreed otherwise by the Engineer.

The submersible pumps shall be supplied and installed complete with bolt-less self-aligning duck foot assemblies giving automatic connection, and rising pipe work to thesump top. All pipe work and fittings inside wet well shall be reinforced thermoset resin.

Each pump shall be provided and installed with stainless steel guide rails, fittings and allnecessary support brackets. A lifting chain made of stainless steel shall be attached toeach pump to enable the pump to be raised and removed from the wet well without thenecessity for personnel entering the well.

Each pump shall be supplied complete with a suitable length of submersible cable. Thelength of the cable shall be so as to allow connection to a connection box adjacent to thewet well.

The submerged cable shall be a multi-core flexible cord, vulcanised rubber insulated withtough rubber sheath and outer PCP sheath to BS 6500.

2.1.6 Progressive Cavity Pumps

2.1.6.1 General

Progressive cavity pumps shall have an output characteristic that is substantially

independent of change in head.

Pumps shall be designed for continuous operation.

2.1.6.2 Casings

Casings shall be of close grained cast iron to BS EN 1561 capable of withstandingpressures that may be produced due to normal operating pressure surges. Flanges shallaccord with BS EN 1092: Part 2.

Casings shall be mounted on base plates manufactured from cast iron. Casings shall beaccurately aligned and located by dowels or machined spigots. Holes shall be provided inthe base plates or stools for foundation bolts.

Casings shall not be integral with the stool or base plate, but shall be designed to allowthe ready removal of the pump complete from the stool or base plate. Easy access tosuction pipe connections must be available.

Stools or base plates shall be fixed to concrete plinths.

2.1.6.3 Glands

Casings shall be sealed against leakage along the rotor shaft by a soft packing stuffingbox, which shall contain a bronze lantern ring to facilitate greasing and efficient sealing ofthe gland.


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The gland housing shall be cast iron and split to facilitate packing of the gland.

A grease stauffer shall be provided for lubrication of the gland.

2.1.6.4 Stator

A resilient stator shall be fitted into a rigid housing and be intimately bonded to it.

Stators shall form a double internal helix of constant circular section in which a singlehelical rotor shall rotate to form progressive cavities.

Stator materials shall be compatible with the liquids and materials being pumped. Statormaterials shall generally be natural rubber, nitrile rubber or Hypalon depending on theapplication.

The stator housing shall be flanged cast iron and jointed to the casing. A flanged deliveryconnection at the free end of the rotor shall be flange jointed to the stator housing. Thesuction flange may be part of the casing or be an interleaving flanged casting betweenstator housing and casing.

Where pumps incorporate long stator housings such housings shall be supported fromthe base plate.

2.1.6.5 Rotating Parts

The rotating parts shall have a smooth finish and the materials shall be compatible withthe liquid and materials being pumped. Rotors shall generally be hard chrome platedstainless steel, tool steel or nitralloy.

Coupling rods shall generally be hard chrome plated mild steel, or hard chrome platedstainless steel. The rod shall be joined to the rotor and input shaft by flexible jointspreferably of the ball and socket type.

Shaft diameters shall be to BS 4506; shaft keyways shall be to BS 4235: Part 1.

The drive shaft shall be supported in heavy duty ball or ball and roller bearings. Bearings

shall have life of 100,000 hours.

Where variable output is required from the pump, this shall be achieved by a hydraulicspeed variator fitted between pump and drive motor. Where fixed speed output isrequired or a compact pump arrangement is required then the drive shall be through antistatic veebelts.

2.1.6.6 Pump Fittings

Pumps shall be equipped with the following fittings as standard requirements:

• A drainage pipe to allow drainage of gland seepage liquid.

• Suction and delivery pressure gauges.

• An engraved nameplate indicating material of rotor and stator, output at normal

speed, and serial number.• A 25 mm plugged tapping on the suction side for manual flushing the pump.

• A pressure relief valve on the delivery side, the discharge of which shall be piped tothe suction pipe.

2.1.7 Screw Pumps

2.1.7.1 Screws

Screw pumps shall comprise a welded steel fabricated central tube with a free start coldformed screw fabricated into a smooth continuous form, welded to the centre tube anddesigned for minimum deflection.


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When it is necessary for the central tube to be constructed of more than one length ofplate, a welded joint shall not be positioned in the centre of the flight but shall bepositioned at each end, and all such joints shall be full penetration butt weld with fatiguedesign to BS 5400: Part 10C. Tube end plates shall be manufactured from Grade 43 steelaccurately machined to carry bearing stub shafts. The central tube shall be watertight.

The spiral blades shall be formed from steel plate. The blades shall be secured to the

centre tube by a continuous weld and the periphery of the screw blade shall be finished toensure a uniform clearance between the screw and trough.

Bearing stub shafts of ample dimensions complete with machined location shoulders andmounting flanges shall be bolted to the tube end plates. Top stub shaft units shall extendthrough the bearing housings to receive the driven half coupling.

Where the upper stub shaft of the screw pump passes through the structure, substantialremovable anti-splash closing plates shall be installed and sealed to the structure. Platesshall be not less than 3 mm thick mild steel, split for ease of removal.

The screw pump shall have a speed of rotation not greater than that given by theequation 50 = ND

0.667 where N is in rpm and D is the outer diameter of the screw in

metres.

2.1.7.2 Screw Pump Bearings

The top bearing shall be arranged for plinth mounting with all loadings transmitted to themotor room floor. It shall be self aligning and designed to support all thrust loads andradial loads at the top of the screw and shall be rated for a life of 100,000 hours under allcombined loadings and, where applicable, speeds imposed by the screw. The servicefactor shall be at least two under maximum load conditions. The bearing shall conform toBS ISO 281.

The bottom bearing shall be designed to withstand all radial forces and end supportloads.

The bottom bearing shall be of bronze or gunmetal sleeve type. The sleeve shallincorporate positive means to prevent rotation of the sleeve bearing.

The bottom bearing shall be supported in a cast iron or fabricated steel housing mountedon a horizontal plinth.

The bottom bearing shall be sealed to prevent the ingress of grit and liquid.

Replacement of the bottom bearing shall be possible without the need to remove thebearing base or the screw or require the use of external carnage.

The bottom bearing shall be suitable for continuous operation either in air or submergedand it shall be automatically lubricated whilst the screw is rotating.

2.1.7.3 Bottom Bearing Lubricator

A positive displacement metering pump, (lubricator), shall be provided for each screwpump to provide a return oil lubrication system for the bottom bearing. The lubricator shallincorporate a means of flow control that shall have a positive minimum setting to preventpremature failure of the bearing. The flow control device shall be provided with lockingfacilities.

The lubricator shall have an independent drive motor interlocked with the respectivescrew pump motor.

The lubricator shall incorporate a reservoir which shall hold sufficient lubricant for sevendays continuous operation of the screw at maximum lubrication rate possible from the


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lubricator. A lubricant contents indicator shall be provided on the reservoir in the form of apositive depth gauge.

A lubricant flow meter shall be installed within the return pipe work which shall provide apulsed output when lubricant is being returned from the bottom bearing. The flow metershall operate in conjunction with a pulse continuity relay which shall stop the pump upona failure of the lubricant system. There shall also be a visible means of indication of the

return flow. A filter shall be provided between the return oil pipe and the reservoir.

Pressure and return pipes shall be stainless steel throughout.

2.1.7.4 Screw Pump Drive System

The gearbox reducing the speed between the prime mover and the screw pump shall beof robust construction having the output shaft at right angles to the input and suitable formounting on a plinth inclined at the same angle as the screw pumps to the horizontal.The concrete plinth shall be provided by the Civil Contractor in accordance with theContractor's design requirements.

The speed reducer shall be of the totally enclosed oil bath lubricated type fitted with oillevel sight glass, dipstick, filler and drain plug, large inspection covers and an oil breather.

Bearings shall be either splash or forced lubricated.

Efficient long life shaft seals shall be fitted to all external shafts to prevent loss oflubricant.

The speed reducer shall be rated for:

• Continuous operation, in the climate and temperature of the place of installation.

A gear design life of 100,000 hours at a service factor of 1.5 at the motor full load rating.All bearings shall be rated for a life of 100,000 hours at speed reducer full torque rating inaccordance with AGMA 6013-A06 Specification and all other combined loadings andspeeds imposed by the screw.

Where speed reducer external cooling equipment is required this shall be a separatesystem to any other cooling system.

Screw pumps shall be driven through flexible couplings, of the pin and buffer type toprevent end thrust and radial loads being transmitted to the speed reducer. Couplingsshall be arranged to allow coupling belts and buffers to be replaced without disturbing thedrive or driven shafts.

A back stop device shall be fitted to the speed reducer shaft to prevent reverse rotation ofthe screw pump under the head of liquid in the flights when the screw pump motor is de-energised.

The screw pump shall be driven by a squirrel cage induction motor. The motor shall beprotected IP55. The motor shall be horizontally mounted.

Power transmission from drive motor to speed reducer shall be through multiple veebelts. Pulley ratios and centres shall be selected to ensure the maximum belt contact andbosses shall be a tight fit on the shafts and shall have fitted keys.

Drive motors shall be mounted on slotted slide rails with belt tensioning screws andlocknuts provided for adjustment.

The complete drive system shall be guarded to prevent accidental contact with movingparts.


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2.1.7.5 Side Profile Plates

A side profile splash guard on the high liquid side of the screw trough shall be provided toprevent liquid running back down the side of the trough.

The guard shall be fabricated from steel plate not less than 5 mm thick. The guard shallbe strengthened and returned to the trough side wall to prevent build up of debris behind

the guard and also allow liquid to run back into the screw.

A channel section shall be provided for casting into the screw trough along the full lengthof the screw pump.

The guard shall be securely bolted to the channel section cast into the civil structure.

2.1.7.6 Trough Profiling

The screw pump trough shall be profiled by welding a steel strip of suitable thicknessalong the complete length of the screw and turning the screw using the Contract motor.

Screeding of the screw pump trough to form the profile will be carried out by the CivilContractor acting under the guidance and direction of the Contractor.

Profile, finish and running clearance between screw pump and trough must be inaccordance with the requirements of the Contractor. Should this not be the case the costof any remedial work shall be split equally between the Contractor and the CivilContractor.

The Contractor shall provide dry running protection for progressive cavity pumps.

The Contractor shall submit details of the proposed system for the approval of theEngineer.

2.1.8 Chemical Dosing Pumps

Chemical dosing pumps shall be of the piston, piston diaphragm or mechanical

diaphragm type. Pump design shall incorporate positive stroke return. The maximumstroking speed shall not exceed 100 strokes per minute.

Stroke adjustment shall be manual, or by an electrical or pneumatic controlled strokepositioner with step less adjustment between zero and maximum stroke length. Whereflow-proportional dosing is required, the variation of output shall be achieved by varyingthe speed of the pump motor and not the pump stroke length.

A stroke length indicator and digital stroke counter shall be fitted.

2.1.9 Submittals

Submit to the Engineer shop drawings and product data. Submittals shall include at leastthe following, where relevant:

• Certified dimensional drawings of each item of equipment and auxiliary apparatusare furnished.

• Certified foundation, pump support and anchor bolt plans and details.

• Schematic electrical wiring diagram and other data as required for complete pumpinstallation.

• Pipe anchors and supports.

• Literature and drawings describing the equipment in sufficient detail, including partslist and materials of construction, to indicate full conformance with the detailspecifications.

• Total weight of pumping unit.


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2.1.9.1 Design Data

Manufacturer's certified rating curves, to satisfy the specified design conditions, showingpump characteristics of discharge, head, brake horsepower, efficiency and guaranteednet positive suction head required (NPSHR). Curves shall show the fully recommendedrange of performance and include shut-off head. This information shall be preparedspecifically for the pump proposed. Catalogue sheets showing a family of curves shall not

be acceptable.

2.1.9.2 Test Reports

• Certified motor test data.

• Tabulated data for the drive motors including rated Hp, full load rpm, power factorand efficiency curves at one-half, three-quarters and full load, service factor and KWinput, including when the pump is at its design point. A certified statement from themotor manufacturer shall be submitted, confirming that the motors are capable ofcontinuous operation on the power supply without affecting their design life forbearings or windings.

• A schedule of the date of shop testing and delivery of the equipment to the job site.

• Description of pump factory test procedures and equipment.

• A statement that the pump will function properly as installed with respect to the

suction piping layout as shown on the Drawings.

2.1.9.3 Operation and Maintenance Data

Complete operating and maintenance instructions shall be furnished for all equipmentincluded under this Section as provided in Division 1. The maintenance instructions shallinclude troubleshooting data and full preventative maintenance schedules and completespare parts lists with ordering information.

2.1.10 Pumping Ancillaries

2.1.10.1 Pressure Gauge Tapings

Each pump set shall be provided with both delivery and suction gauge tapings such that

when fitted they are in an upright position. Each tapping shall be isolated with agun-metal gauge cock.

2.1.10.2 Pressure Gauges

A pressure gauge shall be provided and installed at the above suction and deliverytapings. The gauges shall be of the diaphragm operated sewage installation type.

Pressure gauges shall comprise of brass or black moulded phenol plastic constructionwith acrylic plastic or toughened glass windows. Dials shall be at least 150 mm diameterexcept where fitted to small pumps having branch connections 75 mm internal diameterand below.

100 mm diameter gauges shall be fitted. Internal gauge components shall be of stainlesssteel or other corrosion resistant material with an accuracy of at least + 1 per cent of fullscale. Gauges shall wherever possible operate about their mid scale position. Noaluminium shall be used in the construction of the gauges.

Diaphragms shall be fitted to gauges subjected to liquid containing suspended matter.

Scales shall be calibrated in metres head for water and bar for air. Gauges associatedwith pumps shall be of the compound type for suction branches and the pressure type fordelivery branches.

Gauges shall be fitted with isolation valves and where measuring water pressure theyshall be equipped with a combined isolating valve and air release vent.


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If mounted remotely from the tapping point an isolating valve shall also be installed at thetapping point.

Snubbers shall be fitted to gauges installed on pumps and wherever subjected tofluctuating pressure pulses.

Pressure gauges are to be with stainless steel diaphragm and PTFE coating.

2.1.10.3 Guarding

The Contractor shall include for guards to completely enclose the moving parts of plant.

2.1.10.4 Engraved Nameplates

Each pump shall be provided with engraved nameplates as follows:

Duty Plate: Indicating the type, impeller diameter, output at normal duty, normal dutyhead, speed, serial number and pump curve number.Identification: Corresponding with the pump control panel designation eg 'Pump No 1'.The characters shall not be less than 30 mm high.

2. 2 Surge Vessels

The system shall be provided with a hydro-pneumatic pressure vessel of suitable workingcapacity to provide surge protection and storage. The vessel shall be of the bladder type.The bladder shall be polyurethane and shall be precharged with Nitrogen. The vesselshall be sized to provide sufficient working volume to ensure that the pump starts arelimited, to the requirement in the Particular Mechanical Specification

2.2.1. Vessel

A method statement for the safe charging of the vessel with air shall be included in theOperation and Maintenance Manuals.

Vessels shall be constructed and tested in accordance with PD 5500:2006 (Specificationfor unfired fusion welded pressure vessels) or equivalent International Standard.

Internal weld surfaces shall be dressed for a smooth finish prior to painting.

2.2.2. Bladder

The bladders shall be capable of being readily removed without the need to dismantle thevessel from the installation. A method statement for the safe removal of the bladder shallbe included in the Operation and Maintenance Manuals.

2.2.3. Fittings

Each vessel shall be fitted with:

• 'Schrader' type valve for gas pressurisation;

• Suitably rated safety valve;

• Water drain valve, complete with plug fitted to the open end;

• 100 mm diameter pressure gauge calibrated in bar and meters head, complete withsnubber and isolation valve;

• Gas bleed valve, complete with plug fitted to the open end;

• Water level indicator, suitably marked with the correct operating levels for pumpstopped and operating with varying numbers of pumps under steady stateconditions;

• Flange connection for connecting to the pumping main;


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• Two 25 mm threaded bosses for future instrument connections, fitted with suitableplugs.

The gas charge connections shall be accessible from floor level. The hose assembly forconnecting to pressurising plant shall be provided with each vessel.

The water level indicators shall be suitable for continuous monitoring, i.e. they shall not

allow gas to 'escape' under low water mains pressure conditions without the need toclose isolation valves.

Isolation valves which if accidentally opened allow gas or water to 'escape' shall beprovided with locks.

2.3 Actuators

Actuators shall be well proven for the anticipated environmental conditions. Actuatorsshall be suitable for external installation without the need for sunshades.

Isolating actuators shall have short time ratings appropriate to duty cycle S2 10 min toIEC 34-1, and a maintenance free interval better than 10,000 open/close cycles.

Modulating and inching actuators shall have a rating appropriate to duty cycle type S420% 1200 cycles/hour to IEC 60034-1 and a maintenance free interval better than 50,000hours in normal operation.

Actuated valves and penstocks shall be driven by three phase a.c. electro-mechanicalactuators. Each actuator shall be sized to produce at least 150% of the torquerequirement quoted by the valve or penstock manufacturer.

Valve actuators shall have an index of protection rating IP67 or above and have totallyenclosed drive units and reduction gearing.

Each actuator shall be provided with an integral control and starter system allowing localand remote operation, control and indication. Control systems shall include facilities forvalve modulation using a 4 mA to 20 mA control signal. Local position indication shall beprovided integral with the actuator housing. Actuators shall have position feedbackcircuits giving a 4 mA to 20 mA signal for remote indication. Modulating actuators shallalso have position indication at the local control panel.

The actuators shall also have the facility for hand operation, the use of which willautomatically disengage the electric motor. The hand operation facility shall be capable ofbeing padlocked in the in-operative state.

Limit switches and torque limiting devices shall be incorporated to prevent over running.

Each actuator drive unit shall be complete with integral starter, anti-condensation heater,local operating buttons, local and remote selector switch. A separate termination sectionshall be provided for the glanding and terminating of the supply, control and indicationcables.

A phase discriminator and monitor relay shall be provided.

Cable entries shall be suitable for conduit and fittings to BS EN 61386: Part 1. Cableglands shall be provided for each actuator.

The actuator shall have volt free contacts to indicate when the valve is fully open, fullyclosed or has failed.

2.4 Blowers

Blower sets shall be provided to supply the biological treatment process air requirements.


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The number of blower sets provided shall be sufficient to ensure the range of process airrequirements can be met, and that at peak process airflow requirements one unit is stillavailable as standby.

Blower sets shall be the same model with the same rated capacity.

Each blower set shall be provided with an acoustic enclosure and a surge protection

system. The acoustic enclosure shall limit the noise level to not more than 80 dB(A) whenmeasured at 1 m distance from any point. The enclosure shall be designed to ensure thatadequate cooling of the blower is maintained. The enclosure shall be designed to allowfor ease of access to the blower set without the necessity to lift the complete enclosure,to allow for routine inspection and maintenance procedures.

The blower sets shall be of a proven design with at least five years operationalexperience in similar applications. In addition to single duty applications, the design shallbe proven in applications where two or more units are automatically controlled to meetthe varying air demand.

Materials and equipment of construction shall give a design running life of at least100,000 hours before major maintenance is necessary. Gearbox bearings may have areduced operational life, which shall not be less than 18,000 hours, provided the worknecessary to change the bearings can be safely carried out by general maintenancetechnicians who have limited skill and the work does not involve the precision setting oftolerances.

The impeller, gears and shafts shall be dynamically balanced. The first responsive criticalspeed of the rotating assembly shall be at least 10% above the maximum operatingspeed.

The gears shall have a minimum AGMA service factor of 1.5. A labyrinth oil seal shall befitted to each shaft to prevent oil seepage from the casing under operating and staticconditions. The seals shall be designed to ensure there is no contamination of theprocess air.

The baseplate shall be provided with lifting points to allow the complete set to be handledvia the use of chain slings.

Instrumentation for the safety monitoring