This article is about the test and adjustment of
butterfly valves and common troubleshooting methods.
I. Test and adjustment
1. The manual, pneumatic, hydraulic, and electric components of butterfly valves have been strictly debugged before leaving the factory. When rechecking the sealing performance, the user should evenly fix both sides of the inlet and outlet. It will close the butterfly valve, apply pressure to the inlet side, and observe whether there is leakage at the outlet side or not. Before the pipeline strength test, the butterfly plate should be opened to prevent damage to the sealing pair.
2. Although the
butterfly valve has been strictly inspected and tested before delivery, some products have automatic screw displacement during transportation, which requires readjustment, pneumatic, hydraulic, etc. Please refer to the operating instructions of the supporting drive device
3. (Electric butterfly valves) the opening and closing stroke of the control mechanism has been adjusted well before delivery. In order to prevent the power supply from being connected in the wrong direction, the user should first turn on the manual switch to the half-open position after the power supply is connected for the first time, and then you should press the electric switch to check that the direction of the indicator is consistent with the valve closing direction.
II. Common faults and troubleshooting methods
1. Before installation, confirm whether the product performance and medium flow arrow of our factory is consistent with the moving conditions. You should insert and clean the inner cavity of the valve. No foreign matters are allowed on the sealing ring and butterfly plate. Never close the butterfly plate before cleaning to avoid damaging the sealing ring.
2. It is recommended to use the special flange for butterfly valves, namely the HGJ54-91 socket welding steel flange.
3. The best position for installation in the pipeline is vertical installation, but it cannot be upside down.
4. In use, the flow shall be adjusted and controlled by a worm gearbox.
5. For butterfly valves with many times opening and closing, open the worm gear case cover in about two months to check whether the butter is normal and keep an appropriate amount of butter.
6. Check the connection parts to ensure that they are pressed tightly, which not only ensures the honeybee property of the packing but also ensures the flexible rotation of the valve stem.
7. The metal seal butterfly valve is not suitable for installation at the end of the pipeline. If it must be installed at the end of the pipeline, the outlet flange shall be equipped to prevent the seal ring from overstocking and over-positioning.
8. The valve rod installation and use reaction shall be checked regularly for the valve use effect, and any fault found shall be eliminated in time.
9. See the following table for the possible troubleshooting methods in time:
| Possible troubleshooting methods |
Causes |
Solutions |
| Leaks of Sealing Surfaces |
1. The butterfly plate and sealing surface are jammed with debris.
2. The closing positions of butterfly plates and sealing surfaces are not aligned correctly.
3. The stress of bolts for installing flanges at the outlet side is uneven or does not satisfy the requirements.
4. The pressure test direction does not satisfy the requirements. Eliminate impurities and clean the valve cavity. |
1. Eliminate impurities and clean the valve cavity.
2. Adjust the adjusting screw of the worm gear or electric actuator to ensure the correct closing position of the valve.
3. Check the flange plane and the bolt pressing country, which should be pressed evenly.
4. Apply pressure in the direction of the tip seal. |
| Leakage at both ends of the butterfly valve |
1. Failure of sealing gaskets at both sides
2. The tightening force of the pipe flange is uneven or not compacted.
3. Failure of upper and lower sealing gaskets of sealing ring |
1. Replace the sealing gasket.
2. Pressing flange bolts (uniformly stressed)
3. Remove the pressure ring of the valve and replace the seal ring and the invalid gasket. |
