MODULE 8

1. MODULE 8 System Tests

2. LESSON 1 System Tests

3. Introduction As a propane professional, one of the most important things you do is help keep customers safe. One way to do this is by making sure a customer’s piping system is leak free and operating effectively. You have learned how to install the exterior components of a vapor distribution system. However, once installation is completed, the system is still not ready to be placed into service. A series of checks and tests must be performed by a trained technician before the system can be safely started. Consult your company policy for guidance whenever you perform any test or check of the vapor distribution system.

4. Introduction (cont.) Earlier in this course, you learned how to perform the test for leakage on newly installed exterior piping according to NFPA 58. This lesson provides an overview of the checks and tests required when installing a complete vapor distribution system (exterior and interior) or when restoring operation to existing systems. The CETP course Placing Vapor Distribution Systems and Appliances into Operation provides the training for each test, including specific steps for each procedure. After completing this lesson, you will be able to: • Recognize the different system tests. • State when each check or test should be performed.

5. System Tests In this lesson we will discuss the following system tests: • Test for leakage • Pressure test • Leak check • Leak test • Flow test and • Lock-up test NOTE: These terms are often confused and misused. There are many reasons for this, including code changes and jargon used in different geographic areas. This course uses industry-standard terminology to describe the various vapor distribution tests. It aligns with federal codes and regulations, and strives to standardize these terms within the propane industry.

6. System Tests (cont.) The plumbing codes in many local jurisdictions may require different test pressures and durations. Local codes may also have licensing requirements for the person performing the installation and testing. You must always be aware of the local jurisdiction requirements when you are installing.

7. Test for Leakage and Pressure Test Test for Leakage The test for leakage determines if there are propane leaks in the exterior portion of the piping. It is conducted only on the portion of the exterior piping system governed by NFPA 58 which is from the outlet of the tank vapor service valve to the outlet of the second-stage regulator. One method of testing is to place a pressure gauge before the first-stage regulator and the service valve, and then open the service valve allowing pressure to fill the line. Then, loosen a connection in the line or from a vent valve in the gauge to release a small amount of pressure. The change in pressure will be indicated by the gauge dial.

8. Test for Leakage and Pressure Test (cont.) This test must be performed on all newly installed piping between the tank and the final-stage regulator inlet before the trench is covered. Any new gas piping system, including hoses governed by NFPA 58, must be tested and proven to be free of leaks at not less than the normal operating pressure.

9. Test for Leakage and Pressure Test (cont.) Pressure Test A pressure test is similar to a test for leakage. However, a pressure test checks for leaks in the interiorlines of a vapor distribution system governed by NFPA 54. This covers the lines downstream of the outlet of an integral 2-stage regulator, second-stage regulator, or meter. This test applies pressure of not less than 1½ times the proposed maximum working pressure of the interior piping, but not less than 3 psig. The test medium shall be air, nitrogen, carbon dioxide, or an inert gas. It is performed only on newly-installed interior piping systems or on systems repaired or modified as specified by NFPA 54.

10. Leak Check and Leak Test Leak Check A leak check identifies leaks by applying pressure to the portion of the piping covered by NFPA 54. NFPA 54 covers the piping from the outlet of the point of delivery from the supplier to the outlets of the equipment shutoff valves. The point of delivery can be considered to be the propane container, but the current version of the code defines it as the outlet of the final-stage regulator or the gas meter. The requirement for performing a leak check only applies to the portion of the piping covered by NFPA 54. Therefore, many propane marketers check the entire vapor distribution system, including the appliance connectors, the appliance gas controls, and portions of the system covered by NFPA 58. This test is normally conducted using propane and a pressure gauge or water manometer to monitor a pressure change, which would indicate a leak.

11. Leak Check and Leak Test (cont.) A leak check is performed when a new or modified gas piping system is placed into service, or when there has been an interruption of service, such as a gas outage, gas leak, or regulator replacement. Leak Test A leak test is performed after the test for leakage, pressure test, or leak checkif a leak in the system has been identified. A leak test uses a fluid leak detector or an instrument that can detect propane to determine the specific location of a leak. Once located, the leak must be repaired. The system must be checked again after the repair to determine that it is leak free.

12. Flow and Lock-up Tests When gas appliances are operating, gas is supplied to them through the piping system. The regulators in a piping system ensure the delivery pressure of gas flowing to the appliances is not too high or too low. When all of the appliances are shut off, including any pilot lights, pressure will continue to build in the line(s) unless the regulator stops the flow of gas. Flow and lock-up tests are typically performed on vapor distribution systems during start-up to determine if the piping system and regulator(s) are sized correctly for the estimated load. These tests are also performed to determine whether the inlet pressure to an appliance is sufficient and to verify that a regulator will stop gas flow when there is no call for gas by the appliance.

13. Flow and Lock-up Tests (cont.) Flow Test A flow test measures the pressure downstream of the first-stage and final-stage regulators when the appliances are operating. It determines if the regulators are supplying the amount of gas the system requires. This test is conducted by temporarily installing a water manometer or pressure gauge in the outlet pressure tap of the first-stage regulator and in the distribution line close to the appliance that is furthest away from the final-stage regulator. The manometer or pressure gauge is used to monitor the delivery pressure at the test location when all appliances are turned on. Refer to your company policy for specific procedures.

14. Flow and Lock-up Tests (cont.) Lock-up Test Lock up is the amount of pressure necessary to completely stop the flow of vapor through the first-stage and final-stage regulator inlet orifices, when there is no gas demand. A lock-up test measures the pressure in the lines downstream of the final-stage regulator to ensure that the regulator will shut off the flow of propane when the appliances are not calling for gas. The lock up test is conducted by opening the container service valve and closing all appliance shutoff valves or gas controls. Then the manometer, or pressure gauge, is monitored for any increase in pressure. This continues until the pressure stops rising at or below an acceptable limit.

15. Flow and Lock-up Tests (cont.) These limits are established by the appliance manufacturer or your company policy. You can tell the regulator has shut off the flow of propane when the pressure stops increasing.

16. Module Summary You should remember this important point: After installation of a vapor distribution system is completed and before the system is placed into service, a series of checks and tests must be performed. These must be performed by a trained technician. System tests include test for leakage, pressure test, leak check, leak test, flow test, and lock-up test.