Maintenance and care methods for butterfly valves

The maintenance and care of butterfly valves mainly include daily maintenance, regular maintenance and fault repair, etc. The following are the specific methods:

1. Daily Maintenance

Visual inspection: Regularly inspect the appearance of the butterfly valve to ensure that the valve surface is clean, free of dust, oil stains, rust, etc. Clean the debris on the surface of the valve in time to prevent it from entering the interior of the valve and affecting its normal operation.

Sealing performance inspection: Observe whether there is any medium leakage around the valve. For butterfly valves that transport toxic, harmful, flammable or explosive media, special attention should be paid to the inspection of sealing performance. Once leakage is detected, immediate measures should be taken to handle it.

Operational flexibility inspection: Regularly manually operate the butterfly valve to check if the valve stem rotates smoothly and if there is any jamming or stalling. At the same time, pay attention to the feel during operation. If you find that the operating force has significantly increased or there are abnormal sounds, it may be that there is a problem inside the valve, and further inspection is needed.

2. Regular maintenance

Lubrication and maintenance: Generally, every 3 to 6 months, lubricate the valve stem, bearings and other moving parts of the butterfly valve. Use appropriate grease, such as molybdenum disulfide grease, and apply it to the corresponding parts to reduce friction and ensure the flexibility and ease of valve operation.

Sealing surface inspection and maintenance: Regularly disassemble the valve to check the wear of the sealing surface. If there is slight wear or scratches on the sealing surface, grinding repair can be carried out. If the wear is severe, the sealing ring or sealing pair should be replaced in time to ensure the sealing performance of the valve.

Tightening of connecting parts: Check whether the flange connection bolts, nuts and other connecting parts of the valve are loose. If any are loose, they should be tightened in time. When tightening bolts, the operation should be carried out in accordance with the principles of symmetry and uniformity to avoid valve deformation or poor sealing due to uneven force.

Filter cleaning: If a filter is installed before the butterfly valve, it should be cleaned regularly. Generally, every 1 to 2 months, depending on the cleanliness of the medium, the filter should be removed to remove impurities, dirt and other impurities inside to prevent blockage and affect the normal operation of the valve.

3. Fault Repair

The valve stem does not rotate smoothly: It may be caused by excessive friction between the valve stem and the packing, bearing damage, or foreign objects getting stuck inside the valve, etc. First, check whether the gland of the packing is pressed too tightly and loosen it appropriately. If the problem remains unsolved, check again whether the bearing is damaged. If it is damaged, replace the bearing. Finally, inspect the interior of the valve and remove foreign objects.

Sealing leakage: Damage to the sealing surface, aging of the sealing ring or improper installation, etc., may all lead to sealing leakage. If the sealing surface is damaged, it can be ground or replaced according to the degree of damage. If the sealing ring ages, it needs to be replaced. If the installation is improper, the sealing ring should be reinstalled to ensure the correct installation position and that the compression amount meets the requirements.

The valve cannot be fully opened or closed: It may be caused by improper adjustment of the limit device, deformation of the valve plate, or impurities in the medium blocking the valve plate, etc. First, check the limit device and readjust the limit position; If the valve plate is deformed, it needs to be repaired or replaced. For the situation where impurities get stuck in the valve plate, simply clean the impurities inside the valve.