Check Valve
Spring-loaded, flap-type, and low-noise check valves that prevent backflow of water: brass models from 1/2 inch to 1 inch for pumps, booster sets, and pipework.
Products (6)
- 1/2" Vertical Spring Check Valve – $5.05
- Element Threaded Wastewater Ball Check Valve, DN32, 1.1/4'' – $44.37
- Klepsan Spring-Loaded Vertical Check Valve, Low-Noise, 1/2" – $5.73
- Klepsan Swing Check Valve, 1/2'' – $9.35
- Nortek 1" Vertical Check Valve (1 Side Male Thread) – $19.20
- Spring-Loaded Vertical Check Valve, Male Thread, 1" – $12.06
Brands: Element · Klepsan · Nortek
What does a check valve do?
A check valve (non-return valve) is a valve that allows water to flow in one direction only and automatically blocks reverse flow. It prevents water in the discharge line from flowing back when the pump stops, keeping the pump primed, maintaining pressure in the booster set's pressure tank, and reducing water hammer. It also prevents water from different supply sources from mixing.
Check valve types
- Spring-loaded check valves: Close quickly with the aid of a spring; suitable for installation in any orientation.
- Silent (spring-loaded vertical) check valves: Designed to reduce the banging noise that occurs during closing.
- Flap (clapper) check valves: Operate with a hinged disc; offer low resistance to flow, generally used on horizontal lines.
- Male-threaded and female-threaded models: Selected according to the mating component.
Versions with a strainer used at the end of the pump's suction pipe are referred to as foot valves.
Installation recommendations
The arrow on the check valve body indicates the flow direction; a check valve installed in reverse will completely block water flow. In booster sets, the check valve is generally placed between the pump outlet and the tank connection. Flap-type check valves are fitted to horizontal lines, while spring-loaded models can be installed on horizontal or vertical lines. Adding a Y-strainer upstream of the check valve prevents the disc from failing to close fully due to sand and sediment.
Maintenance
Over time, sediment accumulation in the disc seat and a worn gasket can cause the check valve to leak. The pump restarting shortly after stopping, or rapid pressure drop in the tank, may indicate that the check valve needs inspection. Cleaning is recommended for removable models; replacement is recommended for persistent problems.
Frequently asked questions
The check valve is making noise — is this normal?
A slight sound at the moment of closing is normal; for noticeable banging, silent spring-loaded models can be preferred.
How many bar can a check valve withstand?
Pressure rating varies by model; compare the value in the product specifications with your system's operating pressure.
Which check valve is used on a vertical line?
Spring-loaded check valves can be used safely on vertical lines.
Does a check valve reduce water flow?
Every check valve creates a small amount of resistance; choosing a full-bore model in the correct size minimizes the loss.
What is a valve with built-in check valve?
It is a convenient fitting that combines a ball valve and a check valve in a single body; it is found in the ball valves category.
Where and in what order should a check valve be installed?
A common installation order is check valve first at the pump outlet, followed by the isolation valve; this way the check valve can be removed for maintenance when the valve is closed.