Work Procedure Hydro-Testing of Underground and Overhead Piping
INTRODUCTION:
This procedure is made to elaborate the hydro testing methodology of both underground and above ground pipes.
PROCEDURE:
1. If lines to be insulated or painted before the test, appropriate measures shall be taken to ensure that flanged couplings, intersections & welds, which were not previously tested are neither insulated nor painted so that leaks may be easily detected.
2. The holding time for the pressure in the line will be for minimum 2 hrs or up-to satisfaction of Client and the lines should be tested at 1.5 times the pump pressure.
3. An appropriate vent or drain point shall be provided strictly to remove air from the section.
4. Temporary blind flanges and test blind used to isolate a test system shall be of adequate
thickness to withstand the test pressure. (at least more than 1mm thick than the pipe thickness)
5. Temporary blind flanges and test blinds shall be adequately gasket to prevent damage of flange faces.
6. Valves shall not be used to isolate a test system.
7. Before testing begins, the test package has been declared ready for testing and the system requires to be cleaned, the system shall be flushed with the test medium to remove all dirt and foreign matter.
8. The test pressure gauge shall be located at the visible point of system under test.
9. Drain Point with suitable isolation valve should be provided at the lowest point.
10. Clean water clear from the heavy suspension and foreign matters can be used as test fluid for the hydrant and sprinkler piping.
11. As soon as all connection are closed, put the circuit or line to be tested under pressure by venting, in the case of hydrostatic test any air which may still be present in the circuit by using vent valves.
12. After removal of air, the pressure should be applied through pressure pump steadily and in increments of 25% the lines should be continuously checked usually during each increment.
13. After pressurizing a line, the check shall be performed for the following,
a) Test pressure value (which shall be kept constant throughout the test either by pumping or by venting the pump
b) Welded joints, to detect any leaks (the check is visual if the test fluid is water).
c) Leaks from flanged connection or threaded sprinklers.
d) If leak is found and cannot be eliminated by tightening the connections, the flange seal surface shall be checked are repaired, threaded sprinklers/gasket replaced and the system hydro test repeated prior to pre-commissioning when seal checks shall be performed.
e) Spatter and tack welds resulting from connecting temporary tests supports have been removed.
14. After the hydro test safe dismantling of the test setup to be done.
Quality Checks:
1. Check whether the pressure gauge used is calibrated and has valid.
2. The Readings of the pressure gauge should be Recorded and analyzed in regular intervals at the given holding period of pressure.
3. The Hydro testing report to be documented showing Line Nos., date of test, Joint No., Pressure gauge No., Solution applied, Media of Testing, time, etc. After the event is completed.
Safety Precautions:
1. Check whether continuous supervision is available to carryout work safely.
2. All the people in the vicinity of testing should be informed about the testing.
3. Proper signboards should be placed for the information.
INTRODUCTION:
This procedure is made to elaborate the hydro testing methodology of both underground and above ground pipes.
PROCEDURE:
1. If lines to be insulated or painted before the test, appropriate measures shall be taken to ensure that flanged couplings, intersections & welds, which were not previously tested are neither insulated nor painted so that leaks may be easily detected.
2. The holding time for the pressure in the line will be for minimum 2 hrs or up-to satisfaction of Client and the lines should be tested at 1.5 times the pump pressure.
3. An appropriate vent or drain point shall be provided strictly to remove air from the section.
4. Temporary blind flanges and test blind used to isolate a test system shall be of adequate
thickness to withstand the test pressure. (at least more than 1mm thick than the pipe thickness)
5. Temporary blind flanges and test blinds shall be adequately gasket to prevent damage of flange faces.
6. Valves shall not be used to isolate a test system.
7. Before testing begins, the test package has been declared ready for testing and the system requires to be cleaned, the system shall be flushed with the test medium to remove all dirt and foreign matter.
8. The test pressure gauge shall be located at the visible point of system under test.
9. Drain Point with suitable isolation valve should be provided at the lowest point.
10. Clean water clear from the heavy suspension and foreign matters can be used as test fluid for the hydrant and sprinkler piping.
11. As soon as all connection are closed, put the circuit or line to be tested under pressure by venting, in the case of hydrostatic test any air which may still be present in the circuit by using vent valves.
12. After removal of air, the pressure should be applied through pressure pump steadily and in increments of 25% the lines should be continuously checked usually during each increment.
13. After pressurizing a line, the check shall be performed for the following,
a) Test pressure value (which shall be kept constant throughout the test either by pumping or by venting the pump
b) Welded joints, to detect any leaks (the check is visual if the test fluid is water).
c) Leaks from flanged connection or threaded sprinklers.
d) If leak is found and cannot be eliminated by tightening the connections, the flange seal surface shall be checked are repaired, threaded sprinklers/gasket replaced and the system hydro test repeated prior to pre-commissioning when seal checks shall be performed.
e) Spatter and tack welds resulting from connecting temporary tests supports have been removed.
14. After the hydro test safe dismantling of the test setup to be done.
Quality Checks:
1. Check whether the pressure gauge used is calibrated and has valid.
2. The Readings of the pressure gauge should be Recorded and analyzed in regular intervals at the given holding period of pressure.
3. The Hydro testing report to be documented showing Line Nos., date of test, Joint No., Pressure gauge No., Solution applied, Media of Testing, time, etc. After the event is completed.
Safety Precautions:
1. Check whether continuous supervision is available to carryout work safely.
2. All the people in the vicinity of testing should be informed about the testing.
3. Proper signboards should be placed for the information.
