Welded Threaded Pipe Fittings

The hydrostatic test of Welded Threaded Pipe Fittings is an important means of testing their sealing and strength.The following is a detailed test process:

Preparation before the experiment

Experimental equipment and materials

Prepare a suitable water pressure test bench,which should have stable pressure output and accurate pressure measuring devices.The measuring range should meet the requirements of the test pressure,generally around 1.5 times the test pressure.

Prepare a high-pressure water pump to inject water into the fittings and pressurize them,ensuring that the pump can provide sufficient flow and pressure.

Prepare high-pressure hoses,sealing gaskets,pipe joints,and other connectors to connect the fittings to the test bench,ensuring that their specifications match the fittings and can withstand the test pressure.

Prepare auxiliary measuring tools such as thermometers and stopwatches.

Inspection and installation of pipe fittings

Inspect the appearance of Welded Threaded Pipe Fittings to ensure that there are no obvious defects on the surface,such as cracks,sand holes,pores,etc.

Clean the inner and outer surfaces of the pipe fittings,remove impurities such as oil stains,rust,burrs,etc.,to prevent them from affecting the test results or damaging the test equipment.

Install the welded threaded pipe fittings to be tested correctly on the test bench,use suitable sealing gaskets and pipe joints to ensure a secure connection and good sealing,and avoid leakage during the testing process.

Experimental process

Water injection and exhaust

Slowly open the inlet valve and inject water into the pipe fittings through a high-pressure water pump.The injection speed should not be too fast to avoid water hammer damage to the pipe fittings or equipment.

During the water injection process,pay attention to the discharge of air inside the pipe fittings.An exhaust valve can be installed at the highest point of the pipe fittings.When water continuously flows out from the exhaust valve without any bubbles,it indicates that the air inside the pipe fittings has been basically exhausted,and the exhaust valve should be closed.

Boost operation

Start slowly increasing the pressure,and the pressure should be evenly increased.Generally,the pressure should not exceed 10%of the test pressure per minute.

When the pressure rises to 50%of the test pressure,pause the pressure rise and conduct a preliminary inspection of the pipe fittings and connection parts to check for any abnormal conditions such as leakage or deformation.If any problems are found,the test should be stopped immediately,and the pressure should be relieved before repairing or replacing the pipe fittings and retesting.

If there are no abnormalities,continue to increase the pressure to the test pressure.After reaching the test pressure,maintain the pressure stable for at least 10 minutes to observe the pressure changes of the pipe fittings and whether there is any leakage.

Pressure holding inspection

During the voltage stabilization period,carefully inspect all parts of the pipe fittings with the naked eye or with the help of magnifying glasses and other tools,focusing on the welding parts,threaded connections,sealing surfaces,etc.,to check for signs of leakage such as water droplet leakage and sweating.

At the same time,observe the reading of the pressure measuring device to ensure that the pressure remains stable.If the pressure drops beyond the specified value(generally not exceeding 5%of the test pressure),it indicates that there is a leak or other problem with the pipe fitting,and the cause needs to be identified and addressed.

For some important or large pipe fittings,ultrasonic thickness gauges and other equipment can be used to measure the wall thickness of the pipe fittings during the pressure holding period,and check whether the pipe fittings have abnormal deformation or wall thickness reduction under pressure.

Post experimental processing

Pressure relief and drainage

After the experiment is completed,slowly open the pressure relief valve to discharge the water inside the pipe fittings.The pressure relief speed should not be too fast to avoid damage to the pipe fittings.

When draining,the water should be placed in the designated location to avoid environmental pollution or safety hazards.

Inspection and cleaning of pipe fittings

Perform a visual inspection of the pipe fittings again to see if there are any new defects caused by the test,such as crack propagation,increased deformation,etc.

Clean the water stains and dirt on the surface of the pipe fittings,and apply an appropriate amount of rust proof oil to the threaded parts to prevent rusting.

Test records and reports

Detailed records of various data during the test process,including test pressure,stabilization time,pressure changes,pipe inspection results,etc.

According to the test records,a test report should be prepared,which should include the test date,test personnel,pipe specifications and models,test results,etc.The report should also provide detailed explanations of the problems found and their solutions during the test process.After the test report is reviewed and signed,it will be archived as important information for quality inspection of pipe fittings.