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PUMPS, VALVES & ACTUATORS


LET’S DRINK TO VALVE USE


Tameson outlines the relevant use and certification requirements that should be considered when specifying a valve for drinking water applications in different countries


V


alves are fittings that regulate, direct, and control the direction of fluids passing through a pipe. The valves


that come in contact with drinking water must meet specific design and safety requirements to avoid contamination and health-related issues. Other components such as pipes, fittings, hoses, etc., used to transport drinking water must also be certified and approved for this specific application. Valves come in varying designs, shapes,


materials, and sizes. Depending on your use, cases, and the region you are located, you may choose a specific valve that meets a given set of requirements. The main aspects to pay keen


attention to for drinking water applications include the valve’s


material, performance requirements, certification, valve size, and unique use cases. We’ve covered more about drinking water valve requirements in the sections below. Several types of valves find applications in nearly every environment or setting. Some of the common ones used to control drinking


water include: Ball valves – These


valves contain a ball with


a bore, which, when rotated, helps control water flow. Ball valves are lighter, cheap, and can be used for high pressure and high- temperature applications. However, they can be a bit difficult to clean. Butterfly valves –


These valves serve the same purpose as ball valves, but instead of a ball with a bore, it features a rotating disc. It’s often used to control large volume flows. Check valves – These


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valves are installed in water systems to prevent backflow. In drinking water applications, these valves are used to ensure no backflows to the source or dispensing tanks/sites. Supply stop valves – These are


low-pressure valves used to control water flow to plumbing fixtures. They are also called angle stops or angle valves. Gate valves – Gate valves are used to


completely open or shut off fluid flow. They operate in fully open or completely shut-off positions. Float valves – These valves regulate the


flow/water levels in tanks. It acts as a mechanical liquid-level controller that uses a float to detect changes in the elevation, hence opening or closing a valve. Valves used for drinking water applications


can directly affect the health and well-being of those using the respective water systems. Hence there are several requirements put in place to minimise any health risks. The water valve material, for instance, should be neutral in smell, taste, and colour, plus it should be resistant to water and ozone treatment chemicals. The design should also discourage the


growth of bacteria or the formation of biofilm. In ball valves, this is often achieved by introducing an extra hole to drain any water that could stagnate around the ball. It’s also necessary to check the lead content of these materials to ascertain that it doesn’t pose health risks to those drinking the water. Other factors worth considering as far as


the valve material is concerned are corrosion and wear resistance. Often, the valve housing will be made from brass, while the seals will be made from EPDM or NBR. The seats, on the other hand, should be made from a durable material such as Teflon. And besides the material specifications,


you also want to check the bore size to ensure the valves create no resistance to water flow. You can go for a handle material made of hard plastic or steel as it doesn’t come in contact with drinking water.


Certifications and Regulations Every region or country will have its own safety rules and regulations for valves, hoses, pipes, and fittings for drinking water


2 JULY/AUGUST 2022 | PROCESS & CONTROL A ball valve for use in drinking water applications


applications. Before choosing a valve to use with drinking water, check the manufacturer’s


documentation to ensure the product complies with the different certifications and regulations enforced by the various public and


private entities in your area. Some of the certifications and regulations


to look out for include: National Sanitation Foundation (NSF) –


This is a North American product testing, certification, and inspection organisation that certifies all the plumbing, chemicals, and water treatment equipment that come in contact with drinking water. Kiwa Water Mark – This is a Dutch


certification entity that covers all products that come in contact with drinking water. Water Regulations Advisory Scheme


(WRAS) – this certification body covers components such as plumbing systems, water fittings, and other equipment that supply water to the public in the UK. Attestation De Conformite Sanitaire


(ACS) – this is a French certification and approval body for all equipment/components that come in contact with drinking water. DVGW-W270 – This is a certification and


regulatory body for the drinking water sector in Germany. The entity tests all the drinking water equipment for bacterial growth and other microbe contamination. WaterMark – This is an Australian and


New Zealand certification body that covers plumbing equipment that comes in contact with drinking water. For drinking water applications, it is always


essential to ensure that the water does not get contaminated right from the source to the destination. And since the water being transported may come in contact with pipes, valves, hoses, or fittings, most countries or regions have their certification bodies to ensure these products meet the highest quality and safety standards. When choosing a valve for drinking water applications, always pay attention to the relevant requirements and certifications we have highlighted above.


Tameson tameson.com


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