The check valve should generally be selected according to its installation location, water pressure in front of the valve, airtight performance requirements after closing, and the size of water hammer caused by closing. When the sealing performance after closing is strict, a check valve with a closing spring should be used; when it is required to weaken the closing water hammer, a quick-closing muffler check valve or a slow-closing check valve with a damping device should be used. ;The valve or valve core of the check valve should be able to close by itself under the action of gravity or spring force.
