medical gas general specification

8/2/2019 Medical Gas General Specification

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G:\STANDARD\MI Spec In Progress (OTD )\Medical Gas\Medical Gases Spec.doc Page 1 of 20

MATERIALS

1. General copper tubes, which are used for positives pressure and suction pipelines, shallbe of as drawn seamless tube, manufactured in accordance with British standard

BSEN 1057 (seamless round copper tubes for medical gases or vacuum), AS/NZS 1571,EN 13348, or B 280 for medical gas purposes.

Brand/manufacturer: CRANE & ENFIELD or KEMBLA

NOTE : the installation of suction pipelines using PVC and other similar plastics

material can results in cracks and leakage as the materials degrade with age.

2. Oxygen compability of components. All components of a pipeline system for all medicalgases and suction shall compatible with oxygen under normal working conditions and

shall be clean and free from oil, grease and particulate matter. Components shall

included, but not be limited to, containers, pipes, valves seats, lubricants, fitting and

gaskets.

NOTES:

Appendix D gives recommendations for the use of materials in pipeline systems

Compability involves both combustibility and ease of ignation. Materials that burn in air

will burn violently in pure oxygen, particularly oxygen under pressure. Similarly,

materials that can be ignited by friction at a valve seat or stem packing or by adiabatic

compression produced when oxygen at high pressure is rapidly introduced into a system

initially at low pressure. The requirement of this clause includes components for gasesother than oxygen or oxygen mixtures because it is difficult to segregate materials in

stores and particularly on construction sites during installation.

3. Cleaning of pipelines and componentsGeneral as all pipe supplied in accordance with AS/NZS 1571 are factory cleaned,

degrease and capped prior to delivery, the pipes shall not be cleaned on site, except for

necessary purging operations to remove any particles entrained during installation.

Valves and fitting shall be delivered clean, and shall be protected from

contamination during delivery to the site.

All valves shall have labels attached, stating cleaned for oxygen service

Particular care shall be exercised in the storage and handling of all pipe

fittings. After cutting, pipes shall be temporarily capped or plugged to prevent

contamination while awaiting installation.

On site communication when a fitting or other component becomes contaminated on-

site, it shall be returned to the supplier for cleaning.


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REQUIREMENTS FOR PIPELINES

1. GeneralPipelines and fittings sizes shall be selected to provide the required design flow of the

entire health care facility.

2. Pipeline design pressure and flowsThe nominal design working pressure shall be 415 kPa for medical gas supply, 60 kPa for

medical suction and 1400 kPa for surgical tool gas supply.

Flow requirements should be determined on the basis of discussions with the health care

facility to ascertain the expected and projected gas usage and number of terminal units

required, as the number of terminal units required depends on the particular health care

facilitys requirements.

3. Surgical tool gasThe gas used to drive surgical tools shall be medical breathing air, with a water content of

not more than 25 ppm

NOTES :

i. This level of dryness cannot be achieved by conventional refrigeration drying.ii. Nitrogen and nitrous oxide do not support life and cannot be differentiated by the

commonly used oxygen analyzer. Because of the ever present risk of error of

connection at the input to a pipeline or cross connection (or both) in the pipe-work(following alterations), medical nitrogen is not recommended for used with gas

powered tools in healthcare facilities. Medical breathing air for surgical tools should

have a specific outlet. Tools gas is usually supplied at a pressure about 1400 kPa

which may damage ventilators and other equipment if used as medical breathing air.

iii. Cylinder manifolds are generally the preferred method of supply for surgical tool gasas the dryness requirement of 25 p.p.m of moisture is usually difficult, requires

frequent or continuous monitoring and is expensive to attain, if using compressors.

4.

In-line fittings and valvesWhere in line fittings and valves are used for pipelines the fittings shall not be less than

the bore of the piping connected to them.

Fittings and joints which permit disconnection shall not be installed in any buried

pipeline. Couplings shall at all times be easily accessible for inspection and maintenance.

5. Surgical tools gas regulatorSurgical tool gas outlets should have a variable regulator immediately upstream of the

terminal units. Adjustment of this regulator should be available to medical and nursingstaff within the operating room.


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PIPELINE SHUT OFF VALVES

1. GeneralAll valves in the high pressure side in a medical gas pipeline system shall be slow

opening so that velocity surges are not introduced into the pipeline. Other valves in themedical gas pipeline system, except those in the source of supply and those in terminal

units, should intrinsically indicate the valve status.

NOTE : Ball and butterfly valves are unsuitable on the high pressure side,

prior to the first stage regulator.

2. Valve boxesGeneral, Isolating valves which if unprotected and are readily accessible to unauthorized

persons, shall be installed in secure valve boxes, preferably located for easy use by FireBrigade Officers.

Box windows, Boxes shall have transparent windows, capable of providing access, large

enough to allow visual confirmation of valve status and be able to permit manual

operation of the valve. For easily action and maintenance pull out access window for

opening the box is recommended. The window/door shall be able to provide security with

valves in either the open or closed position and be kept in a secured position at all times,

except when valves are being opened by an authorized person.

NOTE: It may be necessary to remove the handles of valves while

they are in the off position so that the box may be secured.

Labelling, All valves and valve boxes shall carry the name of the gas and the area served.

The box shall be labeled caution (name of medical gas) valves, do not closed except

in emergency or for authorized work. (Name of medical gas) supply to (area served)

Lettering shall be at least 6mm high, of vertical block type block type characters and shall

be easily distinguishable from the background.

Valve box technical specification for MRCCH:

The wall box unit has a front surround to suit varying wall surface thickness. It also

features a pullout polycarbonate access window.

The box can have the access window in place with the valves in either the open or closed

position.

Fully galvanized with finishing polyester powder coating

Fitted with pressure gauge and pressure switches and 3 way valves

Each box is factory assembled to specific requirements :


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Valve size Copper tube size

15mm 12.70 OD

20mm 19.05 OD

25mm 25.40 OD

32mm 31.75 OD

40mm 38.10 OD50mm 50.80 OD

Medical Gas Line valves (lockable)

Materials:

Body and side plates grade 385 brass

Ball Grade 385 brass, hard nickel plated

Stem Grade 303 stainless steel

Seals precison moulded nitrile co polymerClamp plates & handles grade 1018 steel

Tail pipe, copper tube to relevant standard

Operation rotate handle through 90 degree between stop

Maximum working pressure:

Valve size F tail pipe outside diameter & type Max working pressure

(kPa)

15mm 12.70 OD x 0.91 AS 1432 type B 2400 kPa

20mm 19.05 OD x 0.91 to AS 1432 type B 2400 kPa





3. PositioningAll valves should be positioned for convenient operation

The main medical gas and suction supply pipelines shall be provided with an isolating

valve adjacent to the source. Where the source supplies more than one building, isolatingvalves to control supply to each building may be appropriate.

An isolating valve shall be provided in each gas pipeline serving each anaesthetizing

location and special care areas.

NOTES:

i. For the purpose of this clause, the operating room and its associated anestheticroom are considered as one anaesthetizing location.

ii.

For servicing, it may be desirable to have additional isolating valves for the groupof anaesthetizing locations or special care locations.


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PRESSURE GAUGE

Mechanical gauges shall be a minimum 30mm diameter and shall include colour sectors

clearly indicating the acceptable working range. The sectors shall be as follows for the

respect nomina system pressures:

a. 415 kPa nominal system pressure (oxygen, nitrous oxide, breathing air, carbon dioxide,gas mixtures, eg. 50/50 nitrous oxide/oxygen mixtures).

0 375 kPa ..........red

375 460 kPa ................... green

460 to end of scale ....... red

b. 1400 kPa nominal system pressure (surgical tools gas)0 to 1260 kPa ........................... red

1260 to 1550 kPa ...................... green

1540 to end of scale ................... red

c. -60 kPa nominal system pressure (vacuum)0 50 kPa .................................... red

-50 kPa to end of scale ...................green

Gauge layout and colour densites should be chosen to give maximum contrast between gauge

face and level indicator (eg. needle).

Electronic pressure representation screens, whether of the bar type or numerical value type

shall clearly indicate that the displayed value is within or outside the acceptable pressurelimits. The display shall be clearly visible under all background lighting conditions.

TERMINAL UNIT AND CONNECTORS

Each terminal unit for medical gas shall be equipped with a self sealing valve, exceptfor ventury ejector suction which shall be controlled with a flow control valve.

Terminal unit shall be gas specific and not interchangeable with other connectors inthe health care facility

Terminal unit shall be provided with permanent identification which shall take theform of background colour coding in accordance with AS 2700 /refer to pantone

matching system) :

Oxygen white Breathing air black & white Surgical tool air aqua (pantone 632) Nitrogen black Nitrous oxide ultramarine (B21 or equal to pantone 293) Suction primrose (Y21 or equal to pantone 100) AGSS yellow and blue (Y21 & B21 BS5682) Carbon Dioxide green grey (N32 or equal to pantone 5935)


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All gas specific components of the terminal unit shall be permanently identified withgas name in 3mm minimum high letters and shall be legible at a distance of 4 metres.

Each terminal unit except for suction terminal units shall be provided with asecondary shutt of valve incorporated in manner that will allow maintenance of the

maintenance of the terminal unit without loss of gas from the system.

Where multiple terminal units are installed, a minimum of 100mm between individualoutlet center shall be provided to facilitate equipment manipulation, except multiple

terminal units sited on operating room pendants and booms, the minimum distance

between outlet center may be reduced to centres of 70mm.

Technical Specifications of medical gas outlet for MRCCH :

SIS type terminal unit to Australian Standard 2896 Solid Brass body and indexing sleeve Front removable main valve for fast and easy seal replacement Side entry gas supply tube positioned at 45 degree to suit multiple installations Secondary valves that automatically shuts off gas supply when main valve is

removed

Low profile body 20mm allows back to back installation in shallow depth walls Complete with flush mounted wall panels manufactured from 1,5mm grade 302

stainless steel

ALARM

The alarm system has two function, one function is the normal operating alarmsand the other function is the emergency alarms.

These alarms would include the diagnostic signals of the alarm itself to cover thefollowing status level :

a. All systems normal signal indicated that all gas supplies are operatingwithin designed limits that the alarm system it self is operating normally. It

is indicated by a green colour with audible alarm off.

b. All systems normal signal but action required. Indicates that one or more gassupplies have reached a point where operator action e.g reordering of gas isrequired. It is indicated by green colour off and amber colour on (flashing)

with the audible alarm on the suitable area.

c. Emergency condition signal. Indicates an abnormal alarm conditions. Thiswill usually be activation of the emergency supply. If unattended, it could

elevate into a failure of supply. It is indicated by extinction of the green and

amber colour. The red colour shall be on (steady) with the audible alarm on.

This alarm will be in continuous observation areas and may alaso active in

some special care area.

d. Supply failure signal. Indicates a high priority alarm condition whichrequires immediate action. It is indicate by the extinction of the green and


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amber colour. The red colour shall be on (flashing) with the audible alarm

on. This alarm will be in the continuous observation areas and also will be

activate in special care areas.

e. Information/diagnostic conditions signal. Indicates a routine action isrequired to maintain gas supplies or a malfunction of the alarm system hasoccurred. This signal may be linked of the gas signals or be shown on a

separate panel in the same or separate location.

Each signal shall be appropriately labeled with a description of its function andbe clearly visible under all background lighting conditions, including no light

If the audibly of the alarm is adjustable the set point shall be indicatedcontinuously or on operator demand. At minimum setting the volume should be

discernible to a person with normal hearing, above a background white noise

level of 55 dBA at a distance of 3m from the alarm panel.

If means of muting the audible component of the alarm provided, then the mutedperiod before resounding shall not exceed 4h

Visible indication of status and audible signal for low pressure and failure shallbe installed for the medical gas pipeline system. Each visible signal shall indicate

normal conditions and power on with green colour, secondary supply with amber

and emergency condition/supply failure red.

Flashing lights for indication of activation of the secondary supply and for supplyfailure shall be included

For medical breathing air and venture suction, the alarm shall operate when theline pressure falls to 20% below the nominal working pressure.

For vacuum generated suction, the alarm shall operate when the suction pressurefalls 20% from the normal working pressure (changing from 80kPa gauge

pressure to 73kPa gauge pressure)

Area alarm technical specification for MRCCH:

The area alarm Panel is designed to monitor up to 8 local inputs. Both audible and

visual indication of any alarm condition is provided. Networked input information is

obtained from other panels connected to the network.

The main electronics PCB is mounted to a metal backing plate.

The front panel present the operator with the following items:

Three LEDs (1 x Red, 1 x Amber, 1x Green) Three switches (Test, Mute, Audio level check) A single digit 7 segment LED display A twenty digit 5 x 7 dot matrix vacuum fluorescent displayEach local or networked input can be programmed to have a unique message assigned

to it which will be displayed when the inputs is in the alarm condition.


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In addition to the message, one of two LEDs can be selected to provide a steady or

flashing status. If non-alarm condition is satisfied on all inputs used, a common

system normal message is displayed along with the green LED

If more than one alarm condition exists simultaneously, the appropriate messages aredisplayed in sequence, however the highest priority LED (Red) will always be

displayed should one of the messages require it. This warns the operator that an

emergency message is contained in the rotating sequence even if the current message

being displayed is of a low priority.

The number of messages in alarm is also displayed on the single digit 7 seg. Display.

If there are more than 9 alarm messages the 7 seg. Display will flash 9.

The audible alarm is sounded with each new alarm condition detected. It can be

muted using the mute switch, however it will sound again after a predefined time

should the alarm condition still exist.

Local input connections and network connection to the alarm is made via plug in

terminal blocks and 8 way plug/socket respectively.

The terminal blocks and 8 way sockets are mounted on a separate dedicated PCB that

can be suitably mounted at the installation wiring stage. This allow the main

electronics to be kept safely out of harms way until final commissioning of the

system, at which point, the main electronics is plugged into the connector PCB via aribbon cable and a network link cable. If networking is not required, it can be disabled

by removing a plug in link on the connector PCB, the unit then functions as a local

8 input stand alone alarm panel.

Power Consumption:

o Operating voltage : 12 Volts AC +/- 10%o Current consumption : -0,6 Ampso Power consumption: 7 wattso Inputs: all input device should be of a passive natureo No externally generated voltages should be appliedo Maximum current supplied by an input cable: 150 ohmso Relay output: alarm status relay contact rating = 1A @30 V DCo Serial output format: 1200 Baud, 8 Bit, 1 Stop, No parityo Cable type Category 5 UTP Solido Network frequency : 78 kbpso Socket connections: pin numbering runs left to right, applies to both 4 way

RS232 socket and 8 way network sockets:


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Master Alarm technical specification for MRCCH :

The Master Alarm Panel is designed to monitor up to 24 local inputs and up to 150networked inputs. Both audible and visual indication of any alarm condition is

provided. Networked input information is obtained from other panels connected to thenetwork.

The main electronics PCB is mounted to a metal backing plate The front panel presents the operator with the following items:

- A 40 digit 5 x 7 dot matrix vacuum fluorescent display- Three LEDs, 1 x Red, 1 x Amber, 1 x Green- A single digit 7 seg. Display

Each local or networked input can be programmed to have a unique message assignedto it which will be displayed when the input is in the alarm condition

In addition to the message, one of two LEDs can be selected to provide a steady orflashing status. If the non-alarm condition is satisfied on all inputs used, a common

system normal message is displayed along with the green LED. If more than one

alarm condition exists simultaneously, the appropriate messages are displayed in

sequence, however the highest priority LED (Red) will always be displayed should one

of the messages require it.

This warns the operators than an emergency message is contained in the rotatingsequence even if the current message being displayed is of allow priority. A single digit

seven segment display is also provided to display how many messages are in the queue,

if there are more than 9 messages, the number nine will continue to be displayed and

will flash. The audible alarm is sounded with each new alarm condition detected. It can be muted

using the mute switch, however it will sound again after a predefined time should the

alarm condition still exist.

Local input connection to the Master Alarm is made via plug in terminal blocks. Theterminal blocks are mounted on a separate dedicated PCB that can be suitably mounted

at the installation wiring stage. This allows the main electronics to be kept safely out of

harms way until final commissioning of the system, at which point, the main electronics

is plugged into the connector PCB via a ribbon cable.

Network connection is made directly to the main electronics via an 8 way plug. Masteralarm programming is done via a 4 pin RS232 plug and socket that couples it to a

computer. This feature permits full custom set up of messages, LEDs, input type,

Audio Repeat Period, etc.


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SOURCE OF SUPPLY

1. GENERALThe source of supply shall be :a. a system of cylinders and necessary supply equipment assembled as described in

clause 4

b. a cryogenic liquid supply system in accordance with clause 8c. a medical breathing air or medical suction system as described in clause 2.9 and 2.10

respectively

The source of supply shall be protected from over pressurization as described in clause 2.7

2. PROVISION IN CASE OF FAILURE OF SUPPLYSpecial care location for medical gas pipeline system in special care locations where

patients are dependent on specific gases, a complete alternative local source for the area,of such dependent gas or gases shall be installed if only a local area failure alarm is

provided. If in addition an emergency gas supply alarm is provided, the capacity of the

emergency gas supply shall be such that it should continue to supply for a time estimates

to be twice that required to obtain an additional gas supply.

NOTES :

1. Medical advice within the health care facility should be sought on the degree ofprotection of each gas supply for each special care location. Normally, areas with

patients undergoing ventilation should have at least the oxygen and medical breathing

supplies protected. In a high dependency unit, only oxygen may be protected. In

coronary care, the level of protection may be two portable cylinders as alternative

sources.

2. Gas consumption should be estimated as normal average consumption, but the timetaken to obtain an alternative source should be estimated on a worst case basis, i.e. as

occurring late at night, on holidays or weekends.

Cryogenic liquid systems

In cryogenic liquid systems an inlet to the system for connecting a temporary auxiliary

source of gas supply for emergency situations shall be incorporated in a location that is

easily accessible as a service facility inlet. The inlet shall be physically protected to

prevent tampering and unauthorized access and shall have a gas specific inlet.

Additional service facility

Consideration should be given to a second service facility inlet for oxygen, remote to the

primary to the primary source of oxygen, ideally situated adjacent to the user areas, and

adequately protected and accessible to connection of an emergency supply.

3. CYLINDERS AND CYLINDER VALVESCylinders and cylinder valves shall be designed, constructed, tested, and maintained in

accordance with AS 2030.1.1.


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4. CYLINDER SUPPLY SYSTEMGeneral

The cylinder supply system shall consist of an automatic changeover manifold with both

working (primary) side and secondary side of the manifold containing each a minimum of

one working days supply, unless delivery schedules indicate that greater volumes shouldbe held.

Automatic Manifold

The automatic manifold shall be of a design and material suitable for the pressure, gas

and service conditions involved and shall be connected to the gas supply cylinders by

flexible leads manufactured.

This unit simultaneously reducing the cylinder pressure and changing the supply from one

bank of cylinders to the other when cylinder pressure in selected primary bank falls to a

non usable level. Pressure switches between the unit are used to signal via separately

available remote display unit(s), the status of the system. A separate inlet port is providedto allow servicing of all components of the console without interrupting supply to

patients. All units are pressure tested prior to delivery and come complete with a

maintenance and spare parts manual. The high pressure components of the units are

suitable for pressure up to 200 bar.

Technical specification automatic manifold for MRCCH :

Maximum inlet (cylinder) pressure . 23000 kPa

Outlet line pressure :

a. Oxygen/Medical Air/Nitrous Oxide ...... 450 kPab. Surgical tool air ...... 1450 kPaOutlet connection : Male 5/8 SAE flare

Emergency inlet connection .. Sleeve index gas specific as per AS 2896

Terminal unit

Header block connections .. Nitrous oxide M16 x 1.5

Oxygen M18 x 1.5

Medical air M20 x 1.5Tool air M20 x 1.5

Design capacity for :

Oxygen central : 2 x 10 cylinder N2O central : 2 x 3 cylinder N2 central : 2 x 3 cylinderManifold isolation

The manifold system shall be provided with an isolating valve in the low pressure

reticulation piping. A service facility connection shall be provided with an isolating valve

in the low pressure reticulation piping. A service facility connection shall be provided foruse during manifold maintenance or in the event of failure of the manifold pressure

regulators.


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Manifold reset

The manifold shall, in a single action, reset both the primary and secondary sides to their

alternative supply pressures.

Manifold headersEach cylinder connected to the system shall be provided with an individual header block

incorporating a non return valve to minimize the loss of gas in the event of cylinder lead

failure. Each header shall have a gas specific threaded nipple for the connection of the

cylinder lead.

Manifold control panel

The control panel shall contain provision for selection of the primary and secondary bank

of cylinders and shall contain clear operating instructions.

Cylinder rack

The cylinders on a manifold should be mounted upright in a rack with safety retainingchains of straps.

Marking of maximum working pressure

The maximum working pressure of the manifold shall be prominently marked on the

control panel above each group of working cylinders and on all detachable components of

the manifold system e.g. cylinder leads modular headers.

Cylinder lead

Each gas supply cylinder shall be connected to the manifold system by a replaceable

flexible lead manufactured from material which are compatible with the gas, and suitable

for the pressures and service conditions involved. Non metallic flexible leads shall be

fitted with restraining cable or equivalent to prevent hose whip in the event of lead

failure. At the cylinder end, the lead shall have a brazed-on or otherwise permanently

attached gas specific yoke or screwed gas specific in accordance with AS 2472. Non

metallic leads for oxygen service shall have 5 m sintered filter, constructed from a

copper base alloy (monel, copper, brass, or bronze material) fitted to the inlet of this yoke

or connection. At the header block end, it shall have a brazed-on or otherwise

permanently attached ferrule.

NOTES :

Non metallic flexible leads made of chlorinated or fluorinated hydrocarbons are notsuitable for use with oxygen or nitrous oxide for medical use.

Emergency gas supply

For oxygen and medical breathing air gas pipeline system where the source is a cylinder

manifolds that supplies one or more special care locations, the source should have an

emergency supply. Such supply may be the last portion of the gas in the secondary

cylinder bank.

5. REGULATORSSource, main and secondary pipeline pressure regulators (where fitted) shall together be

capable of maintaining the required pressure when delivering flows.


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NOTE: Heating of pressure control regulators or associated pipework may be necessary

under high-flow conditions to reduce frosting and condensation within the control

equipment. Overheating should be avoided.

A filter shall be inserted in the line upstream of the regulator.

6. DESIGN OF GAS CONTROL SYSTEMSControl system shall be designed so that regulators, relief valves, safety valve, pressure

alarm sensors and changeover valves can be maintained and serviced without interrupting

gas supply to the pipeline distribution system.

All supply systems shall have a service facility placed so that appropriate access is

achieved for connection by compressors or alternate sources of supply such as mobile

compressors, manifold cylinders or vacuum-insulted evaporator (VIE). This service

facility shall be protected against unauthorized access.

7. DESIGN OF GAS CONTROL SYSTEMSPrimary pressure safety valve

A primary pressure safety valve shall be installed downstream of the first pressure

regulator in each supply line where the service pressure exceeds 2000 kPa. It shall be

capable of protecting line pressure regulators from pressures exceeding design limits.

Line pressure safety valve

A line pressure safety valve shall be set to lift at a pressure of between 30% and 40%

above nominal working pressure and shall not allow the pressure within the system to

exceed 100% above nominal working pressure under any conditions.

The distribution system shall always be in functional continuity with a pressure safety

valve.

Exhaust

Exhaust from both safety and relief valve shall be vented to a safe place. Venting should

preferably be discharges directly to a safe place outside the building.

8.

CRYOGENIC SYSTEMS

General

The cryogenic supply system shall consist of at least three sources of supply, namely

primary, secondary and emergency supply.

Secondary supply

The secondary supply, which is contained within the liquid oxygen cryogenic vessel,

should contain at least an average days requirements unless delivery schedules indicate

that a greater volume should be held.


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Liquid Oxygen Stationary Tank specification :

Type : vertical Net liquid : 1490 gallons (= 5640 litters) Dimension

Height : 4.8 meters

Diameter : 1.9 meters

WeightTare : 4763 kgs

Oxygen : 11249 kgs

Max. working pressure : 250 psig (17.2 bar/1724kPa)

Emergency supply

The emergency supply should contain at least an average days requirements unless

delivery schedules indicate that a greater volume should be held. The supply shall be so

arranged that, when operating, the gas supply to the pipeline distribution system can be

maintained indefinitely without interruption.

The emergency supply shall consist of at least one of the following systems:

a. A cylinder manifold containing at least two banks ofcylinders

b. A system of permanently manifold cylinder contained in roadtrailers or packs

c. A system of cryogenic vessels or containers e.g vacuuminsulted evaporators (VIEs) portable liquid containers, pallet tanks.

Regardless of which system is selected, the contents of the emergency supply shall be

monitored continuously and shall active an alarm on the warning system when a loss of

25% of contents is detected.

Primary main check valve

Cryogenic supply system shall have a non-return valve in the primary pipeline, upstream

of the point of intersection with the emergency supply pipeline.

Cryogenic liquid vessel connections

Cryogenic liquid vessel fill connections shall be gas specific and non interchangeablebetween services to avoid risk of liquid nitrogen or argon being filled into a liquid oxygen

vessel, or vice versa. Adaptors shall not be used.

9. MEDICAL BREATHING AIR SYSTEMThe central supply system for compressed medical breathing air shall supply air of a

minimum purity as specified in AS 2586. It shall be installed in accordance with the

electrical requirements of AS 3000.

A minimum of two air compressors identical shall be installed, each shall be capable of

supplying the design flow rate of compressed air on its own.

Noise generated from the compressed air plant shall cause sound pressure levels inadjacent areas to exceed levels specified in AS 2107


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Vibration generated from the compressed air plant shall not exceed the levels specified in

AS 2625, parts 1-4.

Where compressed air is supplied by water scaled compressor in order to guarantee

purity, appropriate eliminator shall be installed for water droplets, solids and aerosols.

Compressor with oil lubricated compression chambers shall not be used.

After coolers capable of cooling compressed air to within 15 degree Celsius of the

temperature of the cooling medium should be installed between each compressor and the

air receivers. The after cooler shall be fitted with an automatic drain trap complete with a

by pass for manual draining.

Air receivers

One or more air receivers complying with the design requirements of AS 1210 shall be

installed in the system. To ensure continuity of medical breathing air supply when the

receiver is shut down for survey or maintenance, a manual valve by pass facility shall be

installed. The nominal volume of the receiver and pipework should approximately thedesign flow rate volume per minute of the system. Receiver capacity shall be such that

each compressor start less than 10 times per hour during normal working conditions.

Protective coatings shall not be applied to the internal surface of air receivers.

Air dryness

Air dryness shall be achieved as follows :

a. Air drying air shall be dried by duplex driers to a dew point of less than theminimum recorded ambient temperature or a maximum dewpoint of 2 degree celcius

at pipeline pressure whichever is the drier. The performance of the driers shall be such

that dryness can be achieved with one drier removed for servicing.

b. Alarms an alarm should be included in the system to identify when pipelinehumidity exceeds dryness limits. This alarm shall be located in an appropriate place

for timely intervention by regular maintenance staff.

Air inlet and filtration shall be provided as follows :

a. Air inlet to compressorsA separate air intake with an intake filter shall be provided for each compressor.

Filters shall be type 1 (dry) complying with AS 1324.

b. Final filtersA duplicated final filter assembly complete with isolating valves and pressure

differential gauge shall be provided in the pipeline after the drier, arranged to enablemaintenance or replacement of either filter without interruption to the medical

breathing air supply. Each filter shall be sized for not less than the design flow rate.

Filter medium shall at least be type 1 (dry) complying with AS 1324, with a

penetration not exceeding 0,5% of test dust no. 1, when tested in accordance with AS

1132.5

Air pressure control

Duplicate pressure reducing valves, each sized for the full system requirement shall be

provided in the piping system prior to the plant room distributor header.

Air compressor controlControl shall be arranged so that compressors will supply the system in turn or

simultaneously on demand. Controls shall be provided to activate any additional units


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automatically should the lead unit of the system be incapable of maintaining adequate

supply. Controls shall be arranged so that a failure of one compressor control system will

not interfere with the correct operation of the remaining plant.

Malfunction or incapacity to meet demands shall initiate any alarms.

Air compressors shall each be controlled by an independent pressure switch with

adjustable differential for cut in and cut out pressure or by continuous running of the leadcompressor unloading, with pressure switch control of lagging compressors. An

automatic changeover switch for selection of the lead machine shall be provided for

alternation of the duty machine after each cycle.

Medical Air Central System Technical Specification for MRCCH

NO. ITEM SPECIFICATION

1. Air Compressor A Duplex Medical Air System

Oil free, reciprocating piston, 9.2 l/s, 5.5 kW,

380V/3ph/50Hz, max. working pressure 10

bar.

2. After Cooler 25 liter/second nominal flow, 0.12 kW, max

working pressure 20 bar.

3. Relief Valve Bonze/brass, 1/2 bottom connection

4. Pressure Indicator Line 0-10 bar range, 2.5 diameter

5. Flexible Connection 1 connection, 60 cm length

6. Ball Valve 1 Brass/bronze, 400 kPa

7. Non Return Valve 1 Brass/bronze, 400 kPa

8. Pressure Switch 0-8 bar adjusting pressure

9. Reservoir Tank Capacity : 800 liter, max. pressure 10 bar10. Automatic Drain for Reservoir

Tank

Liquid level sensor system, max. pressure 16

bar

11. Pressure Indicator for Reservoir

Tank

0-10 bar range, 4 diameter

12. Coalescing Filter Retain particle and oil aerosol to the size of

0.01 micron with integrated 1 micron pre filter

13. Air Dryer Air flow : 19 liter/second, pressure drop : 0.23

bar, max. pressure : 14.5, type : refrigerated

dryer

14. Activated Carbon Filter Residual oil content : 0.003 mg/m3

15. Sterile Filter Bacterial retention : LRV > 7/cm2 for T1Coliphagen

16. Air Regulator 0-10 bar range

17. Safety Valve Bronze/brass, 10 bar setting

18. Sample Point Valve Bronze/brass, 400 kPa

10.MEDICAL SUCION SYSTEMSIn the design of suction systems, the cost and construction penalty for oversizing the

pipework is small. The sme is not true of the sizing of the plant. Over sizing of the plant

has a major impact on both cost and construction. For this reason, separate design flowrates for pipelines and for plant calculations should be used.


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Pipeline vacuum system

The design of the suction pipeline system and capacity of the pumps shall be such that an

occluded suction of not less than 60 kPa gauge pressure and a free airflow or not less

than 40L/min shall be achieved at any one suction point.

A minimum of two suction pumps, preferably identical shall be installed with eachcapable of supplying the design flow rate on its own. Suction pump performance shall be

specified in volumetric capacity and free air flow. Noise generated from the plant shall

not cause sound pressure levels in adjacent areas to exceed the levels stated in AS 2107

for health buildings. Vibration generated from the plant shall not exceed the levels

specified in AS 2625 parts 1-4.

Electrical requirements

The suction source shall be installed accordance with the electrical requirements of AS

3000.

Suction receiverWhere a receiver is fitted, its quality of materials, welding and general construction shall

be in accordance with AS 1210. The nominal volume of the receiver and pipework should

approximate the design flowrate volume per minute of the system. Receiver capacity shall

be such that no pumps starts more than 10 times per hour during normal working

conditions.

Pump inlet filters

Pump inlet filters shall be installed to remove solids, particulate matter and free moisture

to prevent damage to suction pumps. A duplicated filter assembly complete with isolating

valves and pressure differential gauge shall be provided in the pipeline, arranged to

enable maintenance or replacement or either filter without interruption to the suction

system. Each filter shall be sized not less than the design flow rate.

Pump discharge

The discharge gases shall be vented outside the pump house to atmosphere well away

from any ventilation intake, window and areas normally frequented.

Suction pump control

Controls shall be provided to activate any additional units automatically should the lead

unit of the system be incapable of maintaining adequate supply.

Controls shall be arranged so that a failure of one pump control system will not interferewith the correct operation of the remaining plant.


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Vacuum System Technical Specification for MRCCH

NO. ITEM SPECIFICATION

1. Vacuum Pump A Duplex Medical Vacuum System

Oil Lubricated Rotary Vane Vacuum Pump,

Capacity : 184 m3/hour

2. Non Return Valve 1 conn. Bronze/Brass

3. Ball Valve 1 Bronze/Brass 400 kPa

4. Flexible Connection 50 cm of length, 1 conn.

5. Vacuum Switch

6. Vacuum Indicator 0-(-760mm Hg), 4 diameter

7. Ball Valve for drain Bronze/Brass 400 kPa

8. Vacuum Tank Capacity : 1000 liter, Depnaker Certificate

9. Bacterial Filter

11.LOCATIONS OF SOURCES OF GAS SUPPLYCryogenic Liquid Systems

The location of cryogenic liquid systems shall comply with the requirements of AS 1894.

Stationary cryogenic system shall not be installed over subterrancan structures such as

underground bunkers and basement rooms and shall be not less than 5 m away from

openings trenches, subterrancan structures, manholes, gullies or sumps and not less than 3

m from public access routes. Stationary cryogenic liquid oxygen vessels shall be installed

in a position which is well ventilated, with the control equipment protected from the

weather and with the area fenced to prevent unauthorized access.

When a cryogenic liquid supply plant is to be filled from road tankers, adequate access

for the vehicles shall be provided. The vehicle standing/discharge area shall be a

minimum of 3 m square concrete apron and of designed strength to withstand any traffic

loads.

All parts of the area about the depot on which any liquid oxygen is likely to spill shall be

paved with smooth trowelled concrete of a designed strength to withstand any traffic load.

Gas Manifold System

Gas manifold systems may be installed either outdoors or inside a building with sample

natural ventilation to open areas, thus ensuring that risk of oxygen enrichment or

deficiency in parts or the building is minimized and that no special hazard exists for

operators in the operation of the system.

12.ENCLOSURES FOR SUPPLY SYSTEMS

INSTALLATION REQUIREMENTS FOR PIPELINES

Riser and Droppers to Terminal Units


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The minimum outside diameter of any dropper or riser line should be 12 mm. The minimum

outside diameter for copper pipes for suction should be 18 mm.

Interconnection

No two medical gas piping systems containing different gases or the same supply the same

system, each shall be connected through a non-return valve at the junction of the source of

supply and the pipelines.

Pipeline Supports

Medical gas pipelines shall be supported at intervals sufficient to prevent sagging or

distortion in accordance with table. Supports shall be of proper strength so that the pipeline

cannot be moved accidentally from its position.

Supports shall be of suitable material, or treated, to prevent corrosion of both pipe and

supports. Medical gas pipelines shall not be used as a support for any other pipelines,

including medical gas pipelines or conduits. However, a common support bracket of

sufficient strength is permitted to independently support each medical gas pipeline. U-bolt

pipe supports shall not be used.Where vertical pipes are exposed in rooms, they shall be secured at floor and ceiling; pipes

up to 25 mm shall have at least two intermediate supports.

Tabel : Intervals Between Pipeline Support

Size of piping,

Outside diameter

mm

Intervals

for horizontal runs,

m

Intervals for

verticals runs,

m

15 1.5 1.8

20 1.8 2.0

25 2.0 2.5

32 2.0 2.0

40 2.5 3.0

50 2.5 3.0

65 2.5 3.5

80 3.0 3.5

90 3.0 4.0

100 and over 4.0 4.0


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medical gas general specification

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