Operational guidelines and code of practice for stainless steel

OGCP Stainless Steel Products – DWI Ref 56.4.477 - INTRODUCTION
INTRODUCTION
This OPERATIONAL GUIDELINES AND CODE OF PRACTICE (OGCP) FOR STAINLESS
STEEL PRODUCTS IN DRINKING WATER SUPPLY document formed part of an application
through the Drinking Water Inspectorate (DWI) Committee on Products and Processes (CPP), to the
(then) Secretary of State for the Environment, Transport and the Regions (now Environment, Food
and Rural Affairs), The Scottish Parliament, The National Assembly for Wales and the Northern
Ireland Assembly for authorisation of the use of stainless steel materials and products, and was
originally submitted to DWI in April 2001. These authorisations were required at the time of
submission under Regulation 25 (1)(a) of the Water Supply (Water Quality) Regulations 1989 and its
equivalents in Scotland and Northern Ireland, and subsequently, Regulation 31 of the Water Supply
(Water Quality) Regulations 2000. This OGCP document was revised in accord with requirements of
the CPP, and now forms part of the conditions of approval for individual stainless steel materials and
products under these Regulations.
This document provides a Code of Practice that identifies all the key requirements with regard to the
use of stainless steel materials and products and provides the framework for contract document
specifications. The Operational Guidelines section of the OGCP describes stainless steel materials and
products in more detail and provides information on essential application, quality assurance and
remedial action issues. The document is the result of a number of years of development work and
experience by the material and product manufacturers, specifiers, suppliers and water industry
engineers. The document may also be regarded as a summary of general “Manufacturers’ Instructions
for Use” (IFU) as indicated in 1.7.8 of DWI Application Form reference 56.4.77.
Stainless steels have excellent corrosion resistance to the majority of the conditions met in water
handling and treatment, providing the correct grade is selected and simple design and fabrication rules
are followed. They also have excellent mechanical properties offering a good combination of
strength, ductility, ease of fabrication and toughness. These attributes result in the following
advantages:
Χ
Χ
There is no dependence upon applied coatings (organic, polymeric, cementitious or metallic)
for corrosion protection. Hence, no allowances for corrosion loss are required at the design
stage, no constituents of the coatings are lost into the water and there is no coating
maintenance.
Their high strength and ductility mean that the weight of a component can be reduced in
many cases, and resistance to impact damage during operations is enhanced.
The purpose of this OGCP is to enable plant designers, installers and operators to identify the key
requirements in selecting the appropriate grade of stainless steel for equipment used for drinking
water treatment and supply and also in their design, fabrication and installation.
SCI © 2002 1
January 2002: Issue 1