What Problems Should Be Paid Attention To During Butterfly Valve Maintenance

The butterfly valve needs regular maintenance to make the butterfly valve work better. Today, the butterfly valve manufacturer will tell you what problems should be paid attention to when the butterfly valve is overhauled.

1. Requirements for valve maintenance:

The surface of the valve stem should be free of pits, scratches and axial grooves. If there are slight scratches, it can be used after polishing and qualified. If the damage is serious, the surface must be repaired; measure the straightness of the valve stem, and straighten or replace it if it is bent ; The axis of the trapezoidal thread of the valve stem and the upper sealing cone surface and the axis of the valve stem meet the requirements; if the head of the valve stem is found to be dented or deformed, it should be repaired in time; the valve stem with drive thread, if it is driven If the thread is damaged, replace it.

2. The maintenance requirements of the sealing surface:

Check the contact surface impression with a display agent on the sealing surface: the impression line of gate valve, stop valve and check valve should be continuous, with a width of not less than 1mm, and the impression is uniform. The limit position of the impression line of the gate valve plate on the sealing surface is not less than 3mm from the outer circle (Including imprint line width). The impression surface of the ball valve is continuous, the width is not less than the outer diameter of the valve body sealing ring, and the impression is even. The repair and grinding of the sealing surface of the valve should be based on the individual grinding of the parts, and the matching grinding should not be used as much as possible. The suitable abrasive should be selected according to the sealing parts. Maintenance requirements for valve body, bonnet and gasket:

The valve seat and the valve body should be connected firmly, tightly and without leakage; the valve plate and the guide rail should be properly matched, and there will be no jamming or derailment at any position; the maximum matching clearance of the flange concave flange in the valve body should meet the requirements; steel ring gasket The contact surface with the sealing surface groove should be colored and checked, and the impression line should be continuous; the flange should be parallel and the installation spacing should meet the requirements; the bolts with tightening torque requirements should be tightened according to the specified torque, and the tightening torque error should not be greater than ±5%.

3, the maintenance requirements of packing:

When installing the V-shaped packing, pay attention to the opening direction of the V-shaped packing, and press it circle by circle until the specified number of groups is added; after the packing is pressed, the packing gland should not be less than 2mm as the stuffing box, and the exposed part should not be less than the packing. The gland can be pressed into 2/3 of the height; after the packing is installed, the rotation and lifting of the valve stem should be flexible, without jamming, and without leakage.

During the overhaul process, the overhaul should be carried out in accordance with the on-site process requirements and quality standards. The overhaul should strictly implement the planned technical measures and safety measures. During the overhaul, the technical data should be recorded, sorted, and classified.

The above is the knowledge shared by butterfly valve manufacturers. I hope it will be helpful to everyone. If you want to know more about butterfly valve knowledge, please contact us as soon as possible.