The swing type flange check valve automatically opens under the action of medium pressure through the valve disc. When the medium flows back, it relies on its own weight and medium pressure to close, which can effectively prevent the reverse flow of the medium from causing impact or damage to pipelines, pumps, valves and other equipment. It is an important protective component in industrial and civil pipeline systems. To fully utilize its functions and extend its service life, attention should be paid to the following usage precautions:
1、 Precautions for installation process
1Clear installation direction
The valve body is marked with an arrow indicating the flow direction of the medium. During installation, it is necessary to ensure that the arrow is consistent with the normal flow direction of the medium, and reverse installation is prohibited.
2Ensure flange sealing
Clean the impurities and burrs on the flange sealing surface before installation, and select suitable sealing gaskets; Tighten the flange bolts evenly in diagonal order to avoid leakage of the sealing surface.
3Avoid pipeline stress
Ensure accurate alignment between the valve and pipeline flange during installation, and prohibit forced docking; When there is thermal expansion and contraction in the pipeline, a compensation device should be installed near the valve.
4Reserved space for valve disc movement
The installation position of the valve should reserve sufficient space to ensure that the valve disc can rotate freely without obstacles when opened.
2、 Precautions during operation
1Control medium parameters
During operation, the temperature and pressure of the medium should not exceed the rated range of the valve, and a filter should be installed upstream of the valve for media containing impurities.
2Smooth start-up and operation
Slowly open the upstream valve during the start-up of the pipeline system to avoid a sudden increase in medium flow rate causing water hammer; Frequent switching of media flow direction is prohibited during operation.
3Regular inspection and observation
Regularly inspect the appearance of valves on a daily basis and check for flange interface leaks; Listen to the running sound without sharp or abnormal noises; The important system regularly records the pressure difference before and after the valve. If the pressure difference rises abnormally, impurities and blockages should be checked.
3、 Maintenance precautions
1Regular cleaning and inspection
Clean the impurities inside the valve during shutdown, with a focus on cleaning the sealing surfaces of the valve disc and seat; Check the wear of the valve disc and seat, repair minor wear by grinding, and replace parts for severe wear.
2Seal maintenance
Regularly inspect the flange sealing gasket and valve stem sealing packing, replace them with seals of the same specifications in a timely manner if they are aged or damaged; When replacing the packing, press it evenly.
3Lubrication of moving parts
Regularly add suitable lubricating oil to moving parts such as valve stems and hinges, with an appropriate amount; Manually test the flexibility of component movement after lubrication.
4、 Precautions for handling abnormal situations
1Medium backflow treatment
If the medium backflow is detected, immediately stop the machine, check the installation direction of the valve first, and then check if the valve disc is stuck or the valve seat is damaged. After troubleshooting, restart.
2Valve blockage treatment
When the valve disc cannot be opened and closed normally, stop the machine and remove the valve, clean the internal impurities, check for loose and deformed hinges, repair and manually test for no blockage before installation.
3Serious leakage treatment
When there is severe leakage from the flange or valve seat, immediately close the upstream valve to cut off the medium. After pressure relief, check the leakage point, repair or replace the components, and test the seal. If there is no leakage, resume operation.