Swing check valves block and regulate the reverse flow of fluid in a system using a hinged swinging disc. Any failure can result in leakage, pressure loss, contamination, overflows, and, in the most extreme circumstances, full system failure since they are employed to prevent the reverse flow of fluids or gases. We’ll talk about some of the most prevalent reasons for swing check valve failures, how to identify them, and how to fix them in the sections below.

• Low-Pressure Applications: Swing check valves are unable to maintain continuous flow in low-flow situations when the system lacks appropriate pressure. Due to a lack of pressure, the disc opens and closes repeatedly, generating excessive wear on the hinge pin and pivot arm to the point where the disc may completely break off. This has the potential to inflict serious harm to downstream devices.
• Water Hammer: Water hammer is defined as an increase in pressure caused by an abrupt pause or shift in the direction of fluid flowing through a valve. Swing check valves, which rely on fluid flow reversal to close fast, are prone to this problem. The disc may break from the swing arm over time due to repetitive shutting of the disc against the valve body. Water hammer can also lead to more major system problems, such as burst pipes and broken fittings.
• Improper Selection: Proper selection and installation of a swing check valve in a fluid system are critical for safe and dependable system functioning. To minimise inefficient functioning and early component failure, the valve chosen should be compatible with the system’s pipework, material, orientation, flow direction, and flow rate. Industry specialists should also consider location and orientation while installing the valve; the valve should not interfere with or be impacted by other system components, and it should be orientated appropriately in regard to flow. In the application where the flow is vertically down, swing check valves will not operate.

There are many ways to determine the faults in swing check valves, some of those are:

• A tapping or hammering sound is produced when the disc opens and shuts repeatedly or aggressively. While the swing check valve may not be damaged at this time, these noises indicate that the disc, swing arm, and hinge pin are under a lot of stress, which will eventually lead to degradation and failure over time.
• Swing check valves may also stick as they degrade. When the valve is continuously tapping at the top of the valve body and peening over the casting material, the valve will get stuck. This repeated operation has the potential to seize the disc and keep it from closing. Leakage or damage to other system components may occur as a result of these operating circumstances.

Regular maintenance of a swing check valve will prevent it from failure. The steps involved in maintenance are as follows:

• Examine the sealing surface for signs of wear and tear. If there is any damage, it should be repaired or replaced.
• Inspect the gasket for any damage or failure and replace it as soon as possible.
• Check to see that the bolts that are attached are secure.
• When checking and fixing the valve while it is dismantled, seat tests must be performed after it is reassembled. Keep careful documentation for future reference.