4 Things You Need to Know About a Leak Check
1. Loss in pressure
A leak check conducted on a vapor distribution system regardless of the type of system shall indicate no loss or gain in pressure for a minimum of 3 minutes. If there is a loss in pressure, the gas supply shall be shut off until the necessary repairs have been made and the system has been successfully retested with no loss or gain in pressure for a minimum of 3 minutes.
2. Insufficient hold time
As stated in the definition for ?Loss in pressure? the hold time is required for a minimum of 3 minutes. Documenting the start time and end time is recommended rather than just documenting the hold time. Do your Safety Inspection forms give the ability to document a start time and end time?
3. Incorrect test procedure
A leak check conducted with a water manometer or other approved gauging device on the low pressure system is considered as an incorrect test procedure if the system is not tested at 9 in. w.c. +/- ? in. w.c. as recommended by NFPA 54 Annex C.
4. Technician only documents leak check for 1 stage not entire system
For multiple stage systems the leak check results should be written for each stage even if the test is just conducted once. This process leaves no doubt that the entire system is gas tight!