Corrosion policy

Regulation 5 of the Provision and Use of Work Equipment Regulations 1998 requires that Every employer shallensure that work equipment is maintained in good repair. To achieve this requirement, the associated guidance tothe Regulations provides further information on three maintenance management options.

OSDs preferred option is that dutyholders use planned preventive maintenance, thereby precluding deterioration.However, where a dutyholder allows components to degrade and/or corrode as part of a condition-based option,performance standards must exist which define the point at which the component needs to be repaired orreplaced. Such performance standards should be quantifiable and capable of being measured effectively andconsistently.

The performance standards need to be supported by sound engineering justification and should be consistent withthe basis of design, taking account of any changes to service conditions. This should include the necessary safety-related strength and/or serviceability requirements of the component necessary to define the quantitativeperformance standard.

Where such components are part of Safety Critical Elements, the components should be verified by an Independent Competent Person. Such verification should include both the justification for and ongoing compliance with the performance standard.

Purpose

This guide is intended to enable OSD inspectors to make consistent judgement on the extent of externalcorrosion related to the installations hydrocarbon systems. The guide identifies a sample of six common formsof external corrosion and provides information on:

n where to look; andn what to look for.

The six areas of concern are:

n corrosion under insulation (CUI);n firewater mains and deluge system;n flanges and plant bolting; n valves;n pipe supports and pipe coatings; andn threaded plugs.

Health and Safety Executive

Offshore external corrosion guide

1 of 5 pages

Corrosion under insulation

Where to look What to look forGeneral target areas n Water traps, eg low points,

brackets, penetrations,support rings

n Areas of personnel trafficn Insulation terminations

Cladding condition n Rusty surface/corrosion holes?n Joint sealant condition?n External condensation/icing?

Penetrations n Sealed/sealant in good (eg branches, supports, condition?structural members) n Signs of water ingress/wet

insulation? n Salt encrustations around

penetrations?Joints n Are the joints generally in

good condition?n Insulation visible through joints?n Deformed/poor fit?

Damaged insulation n Deformed?n Signs of being walked on?n Impact damage?

Corrosion n CUI inspection programme?management n Personnel protection replaced

by cages?n CUI problems/failures?

2 of 5 pagesOffshore external corrosion guide

Health and Safety Executive

Firewater mains and deluge systems

Where to look What to look forGeneral target areas n Mixed metals, non-metallic?

n Spray and monitor nozzlesn Temporary repairsn Valvesn Flanges

Spray and monitor n Blocked?nozzles n Salt encrustations?

n Corrosion products?Temporary repairs n Number?

n Leaking?n Repair type?

Flanges n Leaks?n Dissimilar metals?

Valves n Leaks?n Dissimilar metals?

Non-metallic piping n Leaks?n Joint condition?n Local colour changes?

Corrosion management n Is it a wet or dry system?n What is the inspection programme?n How often is the deluge system

tested?n What is the corrosion

management programme? n What is the failure history?

3 of 5 pagesOffshore external corrosion guide

Health and Safety Executive

Bolts and nuts

Where to look What to look forGeneral target areas n Mixed metals

n Valvesn Flangesn Pumpsn Xmas treesn Corroded bolts/threadsn Fractured boltsn Nuts grossly enlarged by

corrosion productCorrosion protection n Unprotected

n Greasen Denso tapen Galvanisedn Nickel-platedn Corrosion-resistant alloy

Corrosion management n What is the inspection programme?

n What is the failure history?

Valves

Where to look What to look forGeneral target areas n ESDVs

n Xmas treesn Choke valvesn Pressure relief valvesn Drain valvesn Block valves

What to look/ask for n Corroded handles/wheels?n Corroded valve stems?n Leaking stems?n Leaking flanges?n Leaking valve bleed plugs?n Are valves properly supported?n Paint condition?n Corrosion-resistant materials?

Corrosion management n What is the valve test programme?

n What is the inspection programme?

n What is the failure history?

4 of 5 pagesOffshore external corrosion guide

Health and Safety Executive

Pipe supports and pipe coatings

Where to look What to look forGeneral target areas n Piping

n Pipe supportsn Spring supportsn Fretting surfaces

What to look/ask for n Paint condition?n Thick corrosion deposits?n What are the paint and fabric

maintenance programmes?n What action is taken to ensure

areas around pipe supports arepainted?

Corrosion n What external corrosionmanagement problems have there been?

Threaded plugs

Where to look What to look forGeneral target areas n Valve bodies

n Xmas treesn Piping usually low and high

locations on pipe workWhat to look/ask for n Are pipe plugs rare or

numerous?n Are there dissimilar metal

issues?n Condition of threads?n Leaking pipe plugs?n Rust stains?

Corrosion management n Replacement by non-threaded equipment

n No dissimilar metalsn Replacement and thread

inspection programmen What failures have there been?

Published by the Health and Safety Executive 09/06

Health and Safety Executive

5 of 5 pages

For information about health and safety ring HSE's Infoline Tel: 0845 345 0055 Fax: 0845 408 9566 Textphone: 0845 408 9577 e-mail: hse.infoline@natbrit.com or write to HSE Information Services, Caerphilly Business Park, Caerphilly CF83 3GG, or visit the HSE website:www.hse.gov.uk.

This booklet is not available from HSE Books. It can be downloaded from the HSE website at:

www.hse.gov.uk/offshore/index.htm

Crown copyright This publication may be freely reproduced, except for advertising, endorsement or commercial purposes.

First published 09/06. Please acknowledge the source as HSE.