The German Technical and Scientific Association for Gas and Water (DVGW) recently published a new draft of Code of Practice W 332. It deals with the selection, installation and operation of shut-off valves in water distribution systems.
The new DVGW Code of Practice applies to the selection, installation and operation of shut-off valves (gate valves, butterfly valves, taps, valves, backflow preventers and burst pipe valves) in water distribution systems as defined in DVGW W 400-1 (A). It contains specifications on the various types of design and the intended use of various shut-off valves. Furthermore, the installation and operation of the valves are dealt with.
This Code of Practice is supplemented by DVGW Rules W 333 “Tapping valves and tapping operations in water supply systems”, W 334 “Aeration and deaeration of water transport and distribution systems” and W 335 “Pressure, flow and level control in water transport and distribution systems” as well as the existing rules on hydrants.
These technical rules of the DVGW provide the user with a set of rules that should make it easier for him to assess the types of valves offered today with regard to their suitability for the respective area of application.