Product Description
A check valve, clack valve, non-return valve or one-way valve is a
mechanical device, a valve, which normally allows fluid (liquid or
gas) to flow through it in only one direction.Check valves are
two-port valves, meaning they have two openings in the body, one
for fluid to enter and the other for fluid to leave. There are
various types of check valves used in a wide variety of
applications. Check valves are often part of common household
items. Although they are available in a wide range of sizes and
costs, check valves generally are very small, simple, and/or
inexpensive. Check valves work automatically and most are not
controlled by a person or any external control; accordingly, most
do not have any valve handle or stem. The bodies (external shells)
of most check valves are made of plastic or metal.An important
concept in check valves is the cracking pressure which is the
minimum upstream pressure at which the valve will operate.
Typically the check valve is designed for and can therefore be
specified for a specific cracking pressure.Heart valves are
essentially inlet and outlet check valves for the heart ventricles,
since the ventricles act as pumps.