Standard Operating Procedure
Effective Date: REVISES 5/23/91
AUTHORITY: SOMERSET GAS SERVICE
SUBJECT: TESTING PROCEDURES
Testing Procedure for low pressure house piping
POLICY:
Although gas service technicians may not do the actual testing, they are responsible for supervising and setting the limits for this testing by plumbers and other installers.
Among the kinds of tests which are performed on house piping, that is, piping from the meter to the appliance, are:
1.testing new or partially replaced low pressure house piping
2.testing existing low pressure house piping
PROCEDURE I:
Testing Procedures For New or Partially Replace Low Pressure Piping
According to the National Fuel Gas Code Z 223.1 the following procedures should be observed when testing new or partially replace house piping with an operating pressure below 1 pound. (Base pressure measured to a customer is usually below ½ pound.)
- Close all manual shutoff valves ahead of appliances, or disconnect and cap outlet.
- Connect the testing instrument to the inlet of the piping (see Fig. 1) to be tested. Acceptable testing instruments include a properly calibrated gauge, a mercury manometer, or a slope gauge which will read in increments of not greater than one-tenth pound.
- Using air, pressurize the house line to at least 6.0 inches mercury or 3.0 pounds gauge pressure. The piping may also be filled with fuel gas or inert gas but with NO OTHER gas or liquid. OXYGEN SHALL NEVER BE USED!
- The source of pressure shall be isolated before pressure observations are made.
- This test shall be maintained for a minimum of 10 minutes with no drop in pressure.
- Loosen gauge and reduce pressure to “zero” on the piping.
- Open shutoff values to all connected appliance.
- Turn off all pilot and main burner values (see note) on appliances. NOTE: If pilot or main burner valves are not part of the appliance, then proceed with soap testing of the section of the house piping from the shut off valve to the appliance under system operating pressure.
- Close gauge opening and pressurize the house piping to not less than 10.0 inches nor more than 14.0 inches water column.
- The source of pressure shall be isolated before pressure observations are made.
- Maintain this pressure for a minimum of 10 minutes without showing any drop I pressure. This pressure shall be measured by an acceptable test instrument described in Step 2.
- Remove pressure and test instrument from piping.
- Reconnect all piping and the meter.
- When meter is installed and gas pressure applied, test all exposed joints on meter setting with a soap-and -water or leak-detecting solution. NEVER USE AN OPEN FLAME.
- Purge piping of any possible air. Note: DO NOT PURGE INTO ANY CLOSED AREA OR COMBUSTION CHAMBER.
- Record test results for verification on company ticket or work order.
- Handle any leak in accordance with company policy and procedures.
- Repeat tests when leaks have been repaired.
PROCEDURE II
Testing Procedures For Existing Low Pressure House Piping
The following procedures should be observed when testing existing low pressure house piping with an operating pressure below 1 pound.
- Remove meter from the meter loop.
- Connect the test instrument to the inlet of the piping to be tested.
- Turn off all pilot and main burner valves on appliances. Cap all outlets.
- Close gauge opening and pressurize the house piping to not less than 10.0 inches water column nor more than 14.0 inches water column.
- The source of pressure shall be isolated before pressure observations are made.
- Maintain this pressure for a minimum of ten minutes without showing any drop in pressure. This pressure shall be measured by the proper test instrument.
- Remove pressure from piping and remove test instrument.
- When meter is installed and gas pressure applied, soap all exposed joints with a soap and water solution. (NEVER USE AN OPEN FLAME.)
- Test results must be recorded for verification.
- Any leak shall be handled in accordance with your companies policy and procedure and test repeated.
