The National Ground Water Assn. (NGWA) announced that ...
Hayward Industrial offers new thermoplastic valves designed to not fail, stick or jam due to rust or corrosion ? virtually eliminating the possibility of check valve failure and its serious consequences. In addition, they will not contaminate sensitive fluids that come into contact with them.
Once installed, they are designed to provide a long service life, with little or no maintenance required.
They are available in sizes to 4 in. with socket, threaded or flanged connections, and are rated at 150 psi. Viton seals are standard.
The opening pressure of the Hayward check valve is hand adjustable, without tools, over a range of 2 psi to 15 psi. This is a distinct improvement over other spring check valves that either require tools to set or reset them, or need to have a different spring installed to change the opening pressure. A lock ring reliably holds the adjustment after it has been set. The double seal design of the valve ensures seal integrity and long life.
The valves are ready to be used immediately when taken out of the box and do not need to be painted or coated before using, as is required when using metal valves.
The new spring loaded check valve provides positive protection against reversal of flow in a piping system regardless of back pressure. Check valves that are not spring loaded always require some amount of system fluid back pressure to seal properly. If an application cannot product enough back pressure, valves that are not spring loaded will not seal.
Installed after a pump, these valves are designed to prevent unwanted flow of the process fluid once the pump has been turned off ? even if there is no back pressure. For process vessels located inside a secondary containment area, this prevents siphoning of the vessel. For open distribution lines, these new valves are designed to optimize operational efficiencies by preventing unwanted loss of process fluid.
By retaining the process fluid downstream of the pump, the valves greatly reduce the risk of water hammer that could arise if a pump were to be started in an empty, open line.