How to deal with the leakage of the old valve gland in the old building

1. Leakage of valve body.

Cause. 1. The valve body has sand holes or cracks.

2. Tear cracking during valve body repair welding.

Dispose. 1. Polishing the suspected cracks, eroding them with 4% nitric acid solution, and showing them if there are cracks.

2. Dig and repair the cracks.

2. The thread of the valve stem and its fitting thread is damaged or the stem head is broken and the valve stem is bent.

Cause. 1. Improper operation, excessive switch force, failure of the limiting device, and failure of excessive torque protection.

2. The thread fit is too loose or too tight.

3. Too many times of operation and too long service life.

Dispose. 1. Improve the operation, do not use too much force; Check the limiting device and check the torque protection device.

2. Select the appropriate material, and the assembly tolerance meets the requirements.

3. Replace spare parts.

3. Leakage of the joint surface of the bonnet.

Cause. 1. The bolt tightening force is not enough or is tight.

2. The gasket meets the requirements or the gasket is damaged.

3. The joint surface is defective.

Dispose. 1. Tighten the bolts or make the flange clearance of the door cover consistent.

2. Replace the gasket.

3. Dismantle and repair the sealing surface of the door cover.

Fourth, the valve leakage.

Cause. 1. The closure is not strict.

2. Damage to the joint surface.

3. The gap between the valve core and the valve stem is too large, resulting in the sagging of the valve core or poor contact.

4. Poor sealing material or stuck valve core.

Dispose. 1. Improve the operation, re-open or close.

2. The valve is dismantled, and the valve core and valve seat sealing surface are re-ground.

3. Adjust the gap between the valve core and the valve stem or replace the valve disc.

4. The valve disintegrates and eliminates jamming.

5. Replace or surfacing the sealing ring.

First of all, turn off the valve water supply, pry off the screw hole on the valve switch with a screwdriver, remove the switch handle with a screwdriver, remove the valve core with a movable wrench, remove the sealing gasket in the valve core, and clean up the scale and impurities in the valve core. If it is only a leakage caused by scale and impurities, clean it and put it back on. If the gasket is aging, elasticity is insufficient, etc., you need to find a suitable O-ring to add under the ring gasket, and then install it back in turn.

A valve is a pipeline attachment used to open and close pipelines, control the flow direction, regulate and control the parameters (temperature, pressure and flow rate) of the conveyed medium. According to its function, it can be divided into shut-off valves, check valves, regulating valves, etc. Valves are control components in fluid transportation systems, which have the functions of shut-off, regulation, diversion, prevention of backflow, pressure stabilization, diversion or overflow pressure relief.

Valves for fluid control systems range from the simplest shut-off valves to the most complex valves used in automated control systems. Valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, slurries, oils, liquid metals and radioactive media. Valves are also divided into cast iron valves, cast steel valves, stainless steel valves, etc.), chrome-molybdenum steel valves, chrome-molybdenum vanadium steel valves, duplex steel valves, plastic valves, non-standard customized valves, etc.

1. First of all, turn off the valve for water supply, and use a Shanzi screwdriver to pry off the screw hole on the valve switch to cover the cover.

2. Use a screwdriver to remove the switch handle.

3. Remove the valve core with a movable wrench.

4. Remove the sealing gasket in the valve core, and clean up the scale and impurities in the valve core.

5. If it is only a leakage caused by scale and impurities, it can be cleaned and put back on. If the gasket is aging, elasticity is insufficient, etc., it is necessary to grind the gasket for further processing. If you find a suitable O-ring to add under the ring pad, if there is no O-ring, you can just find a piece of rubber skin and cut a suitable size annular gasket underneath, and then put it back in turn.

1. If it is a household valve.

a. If the connection between the valve and the pipeline leaks, wrap more self-adhesive tape at the connection (the best counterclockwise direction when winding, so that it will be tightened more and more tightly when connecting the valve. ）；

b. If the valve itself is leaking, there is also a way, then the valve should be disassembled and added to the seal or O-ring, but it is recommended to replace one more conveniently.

2. If it is an industrial valve.

a. If the industrial valve is leaking, if the valve itself is leaking, then add a sealing ring at the connection between the valve and the pipeline, b. If the valve itself is leaking, it is best to return to the manufacturer for maintenance, if it is not convenient, then only ask the manufacturer to come and repair.

Generally, the sealant gasket is damaged, and it is good after replacement. If it is caused by rusting of cast iron, it is necessary to replace the parts.

Replace the valve. Water and fire are ruthless, prevent micro problems, otherwise slow dripping and slow infiltration will one day cause a catastrophe.