Hyrdostatic Test
Aspire Fire Protection offers low-pressure cylinder hydrostatic testing for all cylinders rated up to 70 bar. Hydrostatic testing is a mandatory process for cylinders that have been in service for over 10 years. This test ensures the cylinder can safely withstand operational pressure without any leaks or structural deformation.
Hydrostatic Test Procedure
A hydrostatic test procedure for pressure vessels involves filling the vessel with water or another suitable liquid and pressurizing it to a specified level to ensure its integrity. The test helps to verify the vessel’s ability to withstand operational pressure without leaks or deformation. The procedure includes preparation, pressurization, leak inspection, and documentation.
Detailed breakdown:
- Preparation:
- Clean the vessel: Remove any debris or contamination.
- Insulate the vessel: Remove any insulation to facilitate visual inspection.
- Install gauges and accessories: Ensure proper placement of pressure gauges, valves and connections.
- Verify safety: Ensure all safety measures are in place, including rope-off areas and proper signage.
- Clean the vessel: Remove any debris or contamination.
- Pressurization:
- Fill with liquid: Fill the vessel with clean water, typically from the lowest point to ensure air bubbles are removed, then install connections.
- Ensure all connections are properly secured. Start the pressure water pump.
- Gradually increase pressure: Slowly increase the pressure using a pump, ensuring the pressure does not exceed the test pressure (normally test pressure be 1.3 to 1.5 times the design pressure/MAWP) according to ASME B31.1 – B31.3 Standards.
- Maintain test pressure: Hold the pressure at the specified level for the specified duration, often 10 minutes or longer.
- Record pressure and temperature: Monitor and record pressure and temperature readings regularly.
- Fill with liquid: Fill the vessel with clean water, typically from the lowest point to ensure air bubbles are removed, then install connections.
- Leak Inspection:
- Reduce pressure: Slowly release the test pressure to allow for visual inspection.
- Visually Inspect: Inspect joints, welds and high-stress areas for leaks.
- Document any leaks: Record the location and severity of any leaks.
- Reduce pressure: Slowly release the test pressure to allow for visual inspection.
- Post-test:
- Repair leaks: Repair any detected leaks and retest the vessel (if repairable).
- Restore insulation: Return insulation to its original position.
- Document results: Record all test results including pressure readings, inspection findings and any repairs made.
- Repair leaks: Repair any detected leaks and retest the vessel (if repairable).
- Final Inspection:
- The vessel is disconnected from the test panel and inverted to drain. Afterward, warm air is used to dry the vessel by heating the heater.
- After the final internal inspection to ensure proper drying, the neck “O” ring is replaced, and the valve is installed.
- The vessel is stamped, filled, leak tested, and the test certificate is completed. The vessel is also tagged to demonstrate that it is safe for use.
- The vessel is disconnected from the test panel and inverted to drain. Afterward, warm air is used to dry the vessel by heating the heater.
Key Considerations:
- The test pressure should be at least 1.3 times the maximum allowable working pressure of the vessel (MAWP).
- The duration of the test may vary depending on the vessel’s size and design.
- Water is the preferred medium for hydrostatic tests, but other liquid can be used in some cases.
- Hydrostatic tests must be performed according to applicable codes and specifications such as ASME.
- Safety is paramount during hydrostatic testing. Always follow proper safety procedures and wear appropriate personal protective equipment.