How to deal with the leakage of stainless steel valve flange
Stainless steel (stainless acid-resistant steel) valve (function: control parts) leakage parts and conditions DN150 valve body (valve body) connection on both sides is also called flange plate or flange bolt (composition: head and screw) leakage, since the flange connection gap is extremely small, it may not be possible to inject sealant through the gap to eliminate leakage.
The sealing construction method of stainless steel (stainless acid-resistant steel) valve (function: control component) is based on the site survey of the leakage site. In order to achieve limited plugging, the fixed fixture method is used to contain the leakage point to form a sealed cavity, and the sealing agent is injected to eliminate the leakage.
1. Fixture design
(1) Fixture structure form determination
① To contain the leakage point, establish a valve body (valve body), also known as a flange plate disc or flange and the sealing cavity between the connecting flanges of the pipe flange. Stainless steel valves can be used to control the flow of various types of fluids such as water, steam, oil, gas, mud, various corrosive media, liquid metals and radioactive fluids. The working pressure of the valve can be from ultra-high pressure of 0.0013MPa to 1000MPa. The temperature ranges from an ultra-low temperature of -269°C to a high temperature of 1430°C. The control component in the fluid transportation system of marine valves and pipelines, which is used to change the cross-section of the passage and the direction of the medium flow. It has the functions of diversion, cut-off, adjustment, and throttling, check, shunt or overflow pressure relief. The valves used for fluid control range from the simplest shut-off valves to various valves used in extremely complex automatic control systems. In order to prevent the leakage of the potential leakage between the valve body and the flange due to the pressure, the annular cavity injection glue is provided at the location where the clamp and the flange of the valve body coincide.
②During the injection process of flange plate or flange flaunching, the clamp is easy to move to the small diameter flange side, so the limit measures of tooth-shaped contact clamping (pointer to the problem solution) are used.
(2) Fixture drawing and related size construction fixture structure. Marine valves are generally used in applications where the working medium is somewhat corrosive. The ability of any valve material to withstand the corrosion of the working medium is relatively limited and is affected by many factors. If the processing technology and heat treatment technology used in the manufacturing process are proper, then the corrosion resistance of this material is guaranteed.
2. Sealant selection and dosage estimation
(1) Sealant selection According to the temperature (leakage) of the leaking system and the characteristics of the leaking part, TXY-18#A sealant is used. The sealant is resistant to temperature, medium (the decisive substance) and injection process performance, easy to establish a uniform (jūn yún) dense seal structure, and the seal can maintain long-term stability (explanation: stable and stable; no change).