Common check valve problems include noise (water hammer), vibration/chattering, reverse flow, sticking, leakage, missing internals, component wear or damage. However, it is worth mentioning that normally the real cause is the wrong size, spring, and/or style for the check valve application.
If it can be isolated in the plumbing then you would apply liquid pressure to the opposite direction of normal flow and see if the liquid comes out. Do you see any fluid going through the check valve? That would be an indication that the check valve is not seating properly.
While typical component lifespans are application specific, manufacturers suggest metal and plastic check valves should be replace every 5-7 years whereas check valves manufactured from rubber may remain fully serviceable for up to 35-50 years.
How Much Does a Check Valve Replacement Cost? Depending on the size and kind of system, most homeowners spend between $135 and $1,000. Professional work costs between $100 and $400, while the gadget itself costs $35 to $600.
Critical check valves are inspected/tested using three main methods: externally, internally and, in unique situations, in-line function testing.
Step 1: Using a vice or an adjustable wrench, screw off and remove the check valve cap. Step 2: Once you get the cap removed, inspect the O-ring, cap and spring inside for any damage, wear or debris. Replace the spring as it is inexpensive and easy to do.
If your check valve isn't correctly triggering the pressure switch to turn the pump on or off, then you're immediately going to have low water pressure issues.
Nearly all well-known pump manufacturers recommend the installation of multiple check valves in water well systems – thus acknowledging the placement of checks at multiple stages along the drop pump is the best way to protect their product application and increase longevity.
A metal disc pivots on a hinge or trunnion to prevent reverse flow. Most larger-scale check valves use this design due to their simplicity. With a life span of five to seven years, these valves are often a component that needs to be replaced frequently.
Reverse flow occurs when water flows upstream of the check valve. This can be extremely costly and dangerous when it occurs at the pump discharge, causing the pump to spin backwards, which damages the pump over time. Prevent this problem by ensuring your valve is working correctly (fast-closing and tight shutoff).
Look for signs of corrosion, rust or mineral build-up. Replace the valve if there are extensive leaks or worn/broken pieces.
The echocardiogram is the most common test to diagnose a problem with the heart valves. Echocardiography, or echo, is a painless test that uses sound waves to create moving pictures of your heart. The pictures show the size and shape of your heart and how well your heart is pumping blood.
In low flow applications, swing check valves are not able to maintain consistent flow when the system does not provide sufficient pressure. The insufficiency of pressure causes the disc to open and close frequently, causing excessive wear on the hinge pin and pivot arm where the disc may break off entirely.
Symptoms of a Failing Check Valve
Check valves will also emit noises as they start to break down. This situation is referred to as “water hammer” and is caused by the disc slamming into the seat of the valve. Water hammer can lead to ruptured pipelines and severe damage.
First, close the inlet valve and open the outlet valve. Then, open the inlet valve and allow the system to fill with fluid. Once the system is full, close the inlet valve and open the outlet valve. The check valve should prevent any fluid from flowing back into the system.
Typically the check valve is designed for and can therefore be specified for a specific cracking pressure. One way to test cracking pressure is to do a simple air pressure test. It estimates the cracking pressure of a spring loaded check valve.
The average cost to replace a main water shut-off valve is $500, but most homeowners pay between $375 and $600 for the service.
Check valves, also called non-return valves, are devices through which fluid flows in only one direction. They function to prevent the reversal of fluid flow (backflow) in the system to which they are applied. Therefore a well check valve failure may result in fluid flowing back into the well.