What is check valve cracking pressure?
Cracking pressure is the inlet pressure at which the first sign of flow occurs. Although often used with liquids, check valves are also used in industrial processes which handle gases and chemicals. Back pressure refers to the difference in pressure between the inlet and the outlet of the valve. When the cracking pressure is reached, the valve will open to allow flow of the material, when it drops, the valve will close.
*Adjustable springs allow for a variety of cracking pressures.
(PSI)
Miniature check valve cracking pressure – 3, 5, 10, 20, 40, 60, 100, 150
Standard check valve cracking pressure – 5, 15, 25, 30, 45
What is a check valve?
A check valve, is a type of valve used in areas of instrumentation tubing or pipeline to control the flow of a gas or liquid. It allows the inner material to flow through a single direction (unidirectional) with minimal pressure drop.
Also known as a non-return valve or two-port valves, they come in many different forms. Examples of this include ball check, stop-check and lift-check valves. Pneumatic non-return valves will be used when a check valve is insufficient, Eg. where there is a risk of chemical spillage or excessive flooding.
Our check valves consist of a main body, spring, poppet, O-ring, body seal and end cap.
Working Pressures
Waverley Brownall check valves are tested for sealing performance based on BS 6755 Pt.1. The tests consist of both low and high pressure shell for up to 4,500 psi, the equivalent of 310 Bar. Miniature check valves feature a working pressure of up to 6000 psi with a cracking pressure from 3 to 350 psi. A minimal pressure drop and bubble-tight shut off are included in both check valve series.
Our check valves are available in sizes from 1/4″ up to 1″ in stainless steel, with a working pressure of up to 3000 psi. This is the equivalent to 206.8427 bar. Optional end connections for thread forms include NPT (National Pipe Taper), BSPT and BSP.
Tables showing pressure drop (psi) vs flow (SCFM) for air flow vs. water can be found in our precision valves catalogue. Sizes tested include 1/4″, 3/8″, 1/2″ and 1″. The O-ring is in material PFTE/Viton with varying temperature range capability. A nominal cracking pressure of 5, 15, 25, 30 and 45 psi with others on request.
Helpful links:
- How does it work? (Check valves via Cameron)
- Hydraulic check valve (Mathworks.com)