WRAS & WRc Approved
What does it mean, WRAS & WRc approved? Potable water or Drinking water solenoid valves that connect directly to UK and Euro zone mains water supply require the appropriate water approvals. The UK accepted approvals are WRAS (Water Regulations Advisory Scheme) and WRc (Water Research Centre) and within the rest of the Euro zone require DVGW and KTW approvals which may include the homogenization's UNI EN 681-1/2003 WB e WA, DVGW W270, DVGW W534, CLP, ACS, KIWA, TGM-LMG 75.
WRAS approved solenoid valves for mains water applications are available in most sizes such as 3/8",1/2",3/4", 1", 11/4, 11/2 and 2" BSP thread for both 2/2 way normally closed and 2 way normally open. WRAS approved solenoid valve Certification and Approvals are only available to water solenoid valves that fully conform to the water regulations, although interestingly enough this only really applies to the non metallic parts of any solenoid valve such as the elastomer diaphragms, O ring seals, gaskets and other seals that come into contact with the water passing through the solenoid valve and typically must comply to BS6920 (Test for water quality)
In the past NBR (Nitrile Buna Rubber) was the accepted standard seal for a WRAS / WRc approved solenoid valve however EPDM (Ethylene Propylene Diene Monomer) is now the accepted seal for drinking water as this has a reduced taste effect on the water passing through the solenoid valve. The other materials of construction of the solenoid valve such as brass and various grades of stainless steel are of no real concern so long as there are no harmful chemicals present or high content of potentially harmful substances such as lead and are of course totally free from potential internal or external leaks and fit for purpose.
My recent discussions with WRAS approval authority confirmed that WRAS are seriously concerned about this flood of very cheap imports of solenoid valves that in some instances are dangerous and hazardous and are a real health and safety concern with regards to domestic water systems.
WRAS Solenoid Valve Tests
WRAS offer a vigorous testing of up to 200,000 open / closed or on / off cycles at maximum pressure and temperature and a 150% over maximum design temperature for leak testing on solenoid valves. Temperature test ranges according to WRAS approval required which are currently 23°C for cold water and anything above 30°C for hot water. Careful consideration has to be given to the application of any water valve, either solenoid, pressure control, flow control, non return valve or filter used with mains water use, so making sure this approval is in place or buying a quality brand is wise when dealing with mains water supply for drinking water applications.
WRc Approval ® "fit for purpose" / WRc Approved solenoid valve certification is a voluntary scheme conducted by the Water Research centre (WRc) to help solenoid valve and other water equipment suppliers and manufacturers demonstrate quality of manufacturing and performance. More importantly products used on water applications that conform to WRc quality, installation and performance will protect our delicate drinking water system from dangerous and harmful debris, chemicals and solvents which could leach dangerously back into the water system and be consumed either directly or indirectly through food processing, manufacturing, cleaning and bottling systems and processes further downstream which even water filtration systems cannot always detect or remove.
WRc ™ approval / WRc Approved and certification offers value to International, Euro Zone and UK companies with existing approvals from USA, Holland, Japan, France, Austria, New Zealand, Australia and Germany.