Oct 31, 2024
Check Valves
A check valve lets fluid flow in one direction and blocks it from flowing backwards. It works automatically without any external power or control.
Function
The valve opens when fluid pushes in the allowed direction. It closes by itself when fluid tries to flow backwards. The closing force comes from gravity, a spring, or the backwards pressure itself.
Main Types
Swing Check Valves use a hinged disc that swings open and closed. They work well in large pipes and cause little resistance to flow.
Ball Check Valves contain a floating ball that moves up to let fluid pass and drops back to block reverse flow. They are simple and reliable.
Lift Check Valves have a guided disc that moves straight up and down. They close quickly and handle high pressures well.
Uses
Check valves protect pumps from damage by stopping fluid from flowing backwards through them when they stop. They keep tanks from draining backwards and maintain pressure in systems. Many industries use them as safety devices.
Important Facts
The valve needs some minimum pressure to open. This is called cracking pressure. The parts that seal can be metal or soft materials depending on what fluid is used. The valve always causes some small pressure loss in the system. Some types must be installed in a specific position to work properly.