How to Hydrotest a 150-lb.-Class Gate Valve

Hydrotest is a high pressure testing using water.

Hydrotesting meets an industry standard for evaluating industrial pressure-rated equipment. Hydrotesting means applying water under pressure for a certain amount of time. Hydrotesting is done to ensure the piece of pressure-rated equipment can withhold internal pressure without cracking or leaking. A gate valve is a type of industrial valve with a central wedge that moves in a channel to control the amount of flow. The 150-lb.-class rating means that the valve is rated for 150 psi (pounds per square inch) of pressure. Hydrotesting is typically done at 150 percent of the rated class so this test will be done at 225 psi.

Things You'll Need

• 2 flanged 150-lb.-class gate valves
• 2-foot sections, 6, of 2-inch pipe spools with flanges
• 4 90-degree elbows, 2-inch, flanged
• 2-inch 300-lb.-class flanged ball valves, 2
• 1/2-inch ball valves, 2 (bleeder valves)
• 10 gallon water tank with pressure gauge
• Air compressor with 300 psi output pressure
• Timer

Instructions

1. 

   Build the test stand out of 2-inch piping.

   Construct the valve test stand by attaching the gate valve between two of the 2-inch pipe spools. Attach the two 1/2-inch ball bleeder valves on either side of the gate valve, pointing down. Add two elbows to the pipe spools and add two more spool pieces. Add the two 2-inch 300-lb.-class ball valves to the sides of the 10-gallon water tank. Connect the remaining pipe spools and elbows to the ball valves on the water tank.

2. Close the two larger ball valves, the bleeder valves and the gate valve. Add water to the water tank until full. Connect the air compressor to the water tank and set the compressor to 225 psi and turn on.

3. When the pressure gauge on the water tank is at 225 psi, open one of the large ball valves on the water tank. This will fill the line up to the gate valve.

4. Open the bleeder valve on the other side of the gate valve and observe any water leakage. Hold for 30 minutes.

5. Turn off the compressor and drain the water after depressurizing the system by slowly opening the bleeder valves. Repeat steps 2 through 4 for the other side of the gate valve.

Tips & Warnings

• Care should be taken to assemble the piping correctly and ensure there are no leaks. Always use caution when opening valves and open them slowly.

• This is a high-pressure system. Only an experienced pipe fitter should assemble high pressure piping.

References

• Peco Valves: Gate Valves