Welded Threaded Pipe Fittings

When there is abnormal pressure in Welded Threaded Pipe Fittings,it is necessary to accurately identify the cause first,and then carry out targeted maintenance according to the specific situation.The following are detailed repair steps and methods:

Fault diagnosis and cause analysis

Comprehensive inspection

Appearance inspection:Carefully inspect the appearance of threaded fittings and check for any obvious damage,such as cracks,sand holes,deformation,etc.These defects may lead to a decrease in the sealing performance of the pipe fittings,resulting in abnormal pressure.At the same time,check the connection parts of the pipe fittings for signs of looseness or leakage.

Inspection of connection parts:Conduct a detailed inspection of the threaded connection parts to ensure that the threads fit well and there are no issues such as slipping or loosening.Check whether the sealing material is intact,whether there is aging,damage or improper installation.For example,rubber gaskets may lose their elasticity due to long-term use,resulting in poor sealing.

Associated equipment inspection:Inspect equipment and pipelines related to threaded fittings,such as valves,pumps,filters,etc.Valve malfunction may lead to improper flow control,thereby affecting pressure;The decrease in pump performance may lead to insufficient pressure;A clogged filter may cause an increase in pressure.

Data monitoring and analysis

Pressure data recording:Use professional pressure monitoring equipment to record the pressure values of pipe fittings at different time periods and observe the trend of pressure changes.Analyze the patterns and amplitudes of pressure fluctuations to determine whether abnormal pressure is persistent or intermittent.

Combined with other parameter analysis:Simultaneously monitor other operating parameters of the pipeline system,such as flow rate,temperature,etc.Analyze the relationship between these parameters and pressure,and identify the possible causes of abnormal pressure.For example,a sudden increase in flow rate may lead to an increase in pressure,while temperature changes may affect the volume and viscosity of the medium,indirectly affecting pressure.

Common fault repair methods

Sealing problem repair

Replace sealing material:If aging,damage or improper installation of the sealing material is found,it should be replaced in a timely manner.Select appropriate sealing materials based on the usage environment and medium characteristics of the pipe fittings,such as rubber sealing gaskets,polytetrafluoroethylene sealing tapes,etc.When replacing the sealing material,ensure that the sealing surface is clean and flat,and install it according to the correct method.

Repair sealing surface:If there is slight damage to the sealing surface,a grinding tool can be used to repair it and restore its flatness.For severely damaged sealing surfaces,machining repair or replacement of fittings may be necessary.

Thread damage repair

Repairing threads:If there is slight wear or thread slippage on the threads,a tap or die can be used to repair them.During the repair process,attention should be paid to the operating methods to avoid further damage to the threads.After repair,check the fit accuracy of the threads to ensure a secure connection.

Replace pipe fittings:If the thread is severely damaged and cannot be repaired,a new threaded pipe fitting needs to be replaced.When replacing pipe fittings,it is necessary to choose products with the same specifications and materials as the original pipe fittings,and install them according to the correct installation method.

Repair of damaged pipe fittings

Welding repair(applicable to some materials):For threaded fittings made of certain materials,if defects such as cracks or sand holes occur,welding can be used for repair.Before welding,the defective area should be cleaned and polished,and suitable welding materials and welding processes should be selected.After welding,a flaw detection inspection should be carried out to ensure the quality of the welding.

Replacement of pipe fittings:If the pipe fitting body is severely damaged and cannot be repaired by welding or other methods,a new pipe fitting needs to be replaced.When replacing pipe fittings,pay attention to the installation position and direction of the fittings to ensure the normal operation of the pipeline system.

Testing and debugging after maintenance

Stress testing

Test preparation:After the maintenance is completed,conduct a pressure test on the pipeline system.Close all valves in the system to ensure a safe testing environment.Connect pressure testing equipment such as pressure gauges,pressure sensors,etc.

Testing process:Slowly increase the pressure and observe the changes in pressure.During the testing process,close attention should be paid to the connection parts and body of the pipe fittings to check for any leakage.The pressure value of the stress test should comply with relevant standards and design requirements,and the testing time should generally not be less than the specified time.

Result judgment:If the pressure remains stable during the testing process and there are no leaks or other issues with the pipe fittings,it indicates that the repair effect is good.If the pressure is unstable or there is a leak,it is necessary to recheck the repair area,identify the problem,and handle it.

System debugging

Flow regulation:After passing the pressure test,adjust the flow of the pipeline system.According to the design requirements of the system,adjust the valve opening to achieve the appropriate flow rate.During the process of regulating flow,it is important to closely monitor changes in pressure to ensure stable pressure.

Operation observation:Open the pipeline system and let it run normally for a period of time to observe the operation of the system.Check the connection parts of the pipe fittings for looseness,leakage,and other issues,and monitor whether the operating parameters such as pressure,flow rate,and temperature are stable.If there are any abnormal situations,the machine should be stopped in a timely manner for inspection and handling.