Views: 0 Author: J-VALVES Publish Time: 2026-02-06 Origin: Site
As a type of industrial valve with high performance and reliability, fully welded ball valves are widely used in the petroleum, natural gas, chemical, metallurgical, electric power and other industries. It is crucial to ensure the reliability of their performance before installation and commissioning, among which pressure testing is a key step.
Fully welded ball valves adopt a fully welded structural design and feature excellent sealing performance and high pressure resistance. Compared with traditional flanged ball valves, fully welded ball valves use welded connections, which not only reduce the risk of leakage but also withstand higher working pressures, thus delivering outstanding performance in harsh operating environments. However, all valves must undergo rigorous pressure testing before use to verify their ability to withstand high-pressure loads during operation.
The main purpose of pressure testing is to verify the sealing performance and structural strength of fully welded ball valves under operating conditions, ensuring their safe and stable operation. Typically, the test pressures include:
Pressure resistance test: To verify whether the valve can operate normally under high pressure.
Sealing test: To ensure the valve's seal remains intact and prevent fluid leakage.
Air and water tightness tests: To check if the valve's sealing surfaces can effectively isolate the medium.
The following preparations must be completed before conducting pressure testing to ensure the smooth progress of the test.
Visual inspection: Check the valve's external condition for integrity and ensure there is no obvious damage or deformation.
Marking and specification verification: Confirm that the valve's model, size, pressure rating, etc., are consistent with the application requirements, especially that the welding quality and design comply with relevant standards.
Function inspection: Check the flexibility of the ball valve's opening and closing functions and ensure there is no jamming of operating components.
The welding quality of fully welded ball valves directly affects their service life and pressure test results. The following inspections should be carried out:
Weld joint inspection: Ensure weld joints are free of defects such as cracks and blowholes.
Weld strength test: Conduct weld strength tests to ensure welds can withstand the specified pressure loads.
Surface inspection: The surface of the welded area should be smooth and free of obvious defects to avoid affecting sealing performance.
The sealing surface is a critical part in the pressure testing of fully welded ball valves. The following inspections should be performed:
Sealing surface finish: Ensure the sealing surface is flat and smooth to prevent leakage caused by unevenness.
Sealing material inspection: Verify that the sealing material meets the specified temperature and pressure resistance requirements.
Sealing test: Air or water tightness testing methods can be used to ensure the integrity of the sealing surface.
Before testing, it is also necessary to inspect the piping connections at both ends of the valve to ensure the valve is firmly connected to the pipeline without loosening, leakage or other issues. Special attention should be paid to the following points during inspection:
Bolt tightening: Ensure all bolts are correctly installed and tightened to avoid connection loosening during the test.
No corrosion and deposits: Ensure there are no corrosive substances or deposits in the pipeline, as these will affect the sealing performance during the test.
Specialized pressure testing equipment is required for pressure testing. Before the test, ensure all equipment functions properly and complies with national and industrial standards, including:
Pressure pump: Ensure the pump's output pressure range is consistent with the valve's rated working pressure.
Pressure gauge: Select a high-precision pressure gauge to ensure accurate measurement of pressure changes during the test.
Leak detection tools: Select gas or liquid leak detection tools according to test requirements to ensure timely detection of micro-leakage points.
After thorough preparations, the actual pressure testing process usually includes the following steps:
Valve installation: Mount the fully welded ball valve on the test pipeline to ensure a firm installation and good sealing.
Pressure application: Slowly increase the pressure via the pressure pump to the set test pressure in stages.
Observation and inspection: During the test, check all valve components for deformation, leakage or abnormal phenomena, especially the sealing surfaces and welded parts.
Pressure holding: Maintain the test pressure for a specified period in accordance with standard requirements, usually 10 minutes or longer, with the specific duration stipulated by different standards.
Pressure relief: After the test, reduce the pressure slowly to ensure the safety of the valve and test equipment.
Several common problems may be encountered during pressure testing, along with their corresponding solutions as follows:
Leakage: If valve leakage is detected during the test, stop the test immediately and inspect the welds, sealing surfaces and connections for defects. Solutions include re-welding or replacing the sealing material.
Insufficient pressure: If the test pressure fails to reach the set standard, the cause may be a malfunction of the test equipment or a defect in the valve itself. It is necessary to check the normal operation of the equipment or verify whether the valve complies with standards.
Pressure testing of fully welded ball valves is an important step to ensure valve quality and safety. A series of preparations must be completed before pressure testing, including equipment inspection, welding quality inspection, sealing surface inspection and so on. Pressure testing can only be conducted when all links are confirmed to comply with standards, so as to ensure the reliability and performance of fully welded ball valves. Scientific and standardized pressure testing not only ensures the normal operation of equipment but also effectively reduces the risk of accidents.
