Quality Control: How to Test Your Valves Before They Ship
2026/7/2 view:
A valve looks perfect on the outside, but that doesn't mean it will hold pressure. If a valve leaks after it is installed in a customer's home or factory, it costs you money to replace it and ruins your brand's reputation. You want a tight testing process to keep your customers happy. Here are the three main ways to check your valves before they leave your warehouse.
If the valve is meant to hold 10 bars of pressure, you might test it at 15 or 20 bars. You watch the pressure gauge for a few minutes. If the needle on the gauge drops even a little bit, it means there is a leak somewhere—either through the body or past the seal. If the pressure stays steady, the valve passes. This is the "gold standard" for ensuring your product is safe to use.
You submerge the closed valve in a clear tank of water and fill the inside with high-pressure air. If the valve has a tiny hole or a bad seal, you will see bubbles coming up to the surface. It is a simple, visual, and very effective way to spot problems. If you don't want to use a water tank, you can use a "pressure decay" machine that detects even the smallest drop in air pressure through an electronic sensor.
Pick a random sample from every batch—maybe 5 or 10 valves for every 500 you make. Turn the handle from fully open to fully closed multiple times. It should feel smooth, with no grinding or sticking. Check the torque as well. If it is difficult to turn, the internal ball or seal might be too tight and will wear out the handle or stem over time.
When a customer calls to tell you that a valve is faulty, you can look at your records and determine what batch it was from and who tested it. This allows you to determine the root cause, whether it be a tool wearing out or a bad batch of seals. Catching these problems in your factory means you can be sure your customers are only getting the best, most reliable valves.
The Pressure Test (Hydrostatic Test)
This is the most important test for any valve. You fill the valve with water or oil and then use a pump to increase the pressure to a level higher than the valve will ever see in the real world.If the valve is meant to hold 10 bars of pressure, you might test it at 15 or 20 bars. You watch the pressure gauge for a few minutes. If the needle on the gauge drops even a little bit, it means there is a leak somewhere—either through the body or past the seal. If the pressure stays steady, the valve passes. This is the "gold standard" for ensuring your product is safe to use.
The Air Leak Test (Pneumatic Test)
Water testing is great, but it makes the valves wet and requires a drying process before packing. For smaller fittings or valves that need to be perfectly dry, many factories use an air leak test.You submerge the closed valve in a clear tank of water and fill the inside with high-pressure air. If the valve has a tiny hole or a bad seal, you will see bubbles coming up to the surface. It is a simple, visual, and very effective way to spot problems. If you don't want to use a water tank, you can use a "pressure decay" machine that detects even the smallest drop in air pressure through an electronic sensor.
The "Swing and Torque" Check
Sometimes a valve holds pressure but is hard to turn. A valve that is too "stiff" will frustrate the person who installs it. You should have a simple checklist for how the valve feels to operate.Pick a random sample from every batch—maybe 5 or 10 valves for every 500 you make. Turn the handle from fully open to fully closed multiple times. It should feel smooth, with no grinding or sticking. Check the torque as well. If it is difficult to turn, the internal ball or seal might be too tight and will wear out the handle or stem over time.
Keeping Good Records
Testing is only useful if you track the results. Create a simple "Pass/Fail" sheet for each batch of valves. Note the date, the batch number, and who did the testing.When a customer calls to tell you that a valve is faulty, you can look at your records and determine what batch it was from and who tested it. This allows you to determine the root cause, whether it be a tool wearing out or a bad batch of seals. Catching these problems in your factory means you can be sure your customers are only getting the best, most reliable valves.
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