How to Deal with Gate Valve Leakage?

Gate valve is the most common industrial valve, widely used in petroleum, petrochemical, power station, long-distance pipeline and shipbuilding and other industrial fields. As a fluid control device, the gate valve opening and closing part is the gate, which can switch the opening and closing state through the up and down movement of the gate, thus realizing the function of cutting off or connecting the pipeline intermediary. Understanding the structure and operating principle of gate valves can help us operate gate valves correctly and better master the operating state of gate valves. In case of leakage of gate valves, correct disposal methods can be adopted the first time to reduce economic losses and reduce the probability of accidents. Gate valve suppliers explain how to deal with gate valve leakage.

Cause of gate valve leakage

1. The medium corrodes the wedge seal ring causing leakage in the gate valve

Needed in the design of wedge ring is more pay attention to the strength and corrosion resistance of sealing ring, sealing ring surface hardness than the bonnet seal layer hardness smaller, but also conform to the conditions in the external force can occur under the action of plastic deformation, the long time running in the process of corrosion medium can also wedge ring, triggering gate valve leakage.

2. Valve leakage due to body defects

Casting valve body often appears casting defects, such as air holes, slag, cracks, sand holes, etc., if these defects are not found in the factory, or not taken the correct repair measures, in the on-site use process will appear the valve leakage.

3. Low machining accuracy of the wedge seal ring causes internal leakage of the valve

Wedge seals can be divided into two categories, the first hard seal, also known as a metal wedge ring; The second is a soft seal, also known as a composite graphite wedge ring. If the accuracy of the wedge seal ring is low, it is easy to cause leakage in the gate valve.

Gate valve leakage treatment measures

1. Check actuator zero

The zero setting of the actuator is not accurate, and the full closure of the valve is not reached. Manually open and close the valve, and then adjust the actuator zero to ensure that the actuator can accurately open or close the valve fully.

2. Weld the clearance between the end face, stuffing box, and pressing plate of the valve body

Since the valve seal leakage treatment needs to remove the valve handwheel and framework, the first thing to cooperate with good technology personnel to grasp and adjustment of the operation condition of the site, and then the valve is opened entirely, remove valve bracket on fixed bolt again, rotary valve frame has been clear about the stem without the change of the rising and falling, began to remove off the valve. Removed after the valve, the valve of the pressure plate parts above the valve body, and to carry on seal the gap between clamp and body and the welding work, out of consideration of leak location after valve frame of back pack process, welding gap size should be between 5 mm to 8 mm advisable, and welding Angle and the position of the pressure plate is 45 degrees Angle of the state, and according to actual assembly conditions.