Q. How do I test a spring pilot?
A. The easiest way to test a pilot operated valve is to disconnect the pilot line and observe the pilot’s operation.
Keep in mind you are handling steam. Use proper safety precautions.
When you turn the adjusting nuts in, the pilot valve should open and steam should shoot out the end of the tube. When you back out the adjusting nuts, the pilot should close. Only a small leakage is acceptable.
Q. How do I test the main valve diaphragm?
A. You can test for leaks in the main valve diaphragms in line. First, disconnect the copper tubing to the main valve diaphragm. Slowly open the bypass valve to load downstream steam pressure. If the diaphragms are bad, steam will blow through the diaphragm and out the bottom of the main valve.