A check valve, also called a one-way valve, is a device that allows the flow of fluids to move only in one direction. The primary purpose of a check valve is to prevent backflow in the system. Check valves are cheap, effective, and easy solutions to a potential issue. Backflow can cause a problem if the flow is contaminated and, therefore, contaminates the media upstream. For example, a sewer line will have a non-return valve to ensure that waste can leave but not re-enter the system it came from. Figure 1 shows an example of a check valve.
There are various sizes, designs, and materials to ensure there is a check valve for every application. Two-way check valves are commonly used. Check valves with vents are used as three-way check valves to protect the incoming water supply from contamination caused by backflow. The atmospheric vent allows the disposal of purged water into an existing drain. An arrow on its bonnet indicates the check valve flow direction.
-Backflow should be avoided. -Capable of withstanding both high and low pressures.
-Ability can be utilized horizontally and vertically as a backup and safety system.
-Self-actuated.
-Quick to react.
-Backflow protection is necessary to avoid damage to pumps and compressors.
-Reduce downtime and production losses.
-Water hammer can be avoided.
-Reduce the likelihood of unexpected valve failure.
-Maintenance expenditures are reduced.
-There are only a few moving pieces.
-A smaller carbon footprint.
-Adaptable to varying flow conditions.
-Does not need the use of electricity to function.
A check valve is basically a one-way valve, in which the flow can run freely one way, but if the flow turns, the valve will close to protect the piping, other valves, pumps etc. If the flow turns and no check valve is installed, water hammer can occur.
In pipes and similar devices and equipment, check valves are generally used to prevent a reverse flow by allowing materials or fluids to flow in only one direction. Despite their various forms, sizes, and functions, these valves generally operate based on the same principle.
The primary components of a check valve include the Body,Body Seats,Gasket,Cover Plate,Hinge,Nuts,Washer.
| DN (mm) |
50 |
65 |
80 |
100 |
125 |
150 |
200 |
250 |
300 |
| L (mm) |
100 |
120 |
140 |
170 |
200 |
230 |
301 |
370 |
410 |
| ΦE (mm) |
50 |
65 |
80 |
101 |
127 |
145 |
194 |
245 |
300 |
| ΦC (mm) |
165 |
185 |
200 |
220 |
250 |
285 |
340 |
405 |
460 |
| ΦD (mm) |
PN10 |
Φ125 |
Φ145 |
Φ160 |
Φ180 |
Φ210 |
Φ240 |
Φ295 |
Φ350 |
Φ400 |
| PN16 |
Φ355 |
Φ410 |
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