What is the reason of flange seal failure? How to prevent flange leakage?

Analysis of leakage of flange seal  and its Prevention 

Abstract: By analyzing the causes of leakage of flange seal, find out the prevention and solution.

Key words: flange  seal  leakage

Flange connection is widely used in the pipeline connection, such as  in gas, oil, water supply and drainage pipes. There many different types of flanges such as SAE flanges (code 61/62 flanges), Slip on flanges, Lapped flanges, Weld neck flanges, and so on.

As the leakage of flange seal can cause the transmission of materials, gas leakage, pollution, and even cause a major fire or personal injury accidents, it must pay attention to the flange seal. This paper analyzes the factors that cause leakage of flange  and puts forward the solution to the solution.

First, the flange

1,  Sealing surface of flange exists in several forms

(1) Flat sealing surface is a smooth plane, usually in the plane with 2-3 concentric groove, tighten the bolt, the gasket material is easy to both inside and outside the squeeze, not easy to compact, only for the pressure is not high , Non-toxic media, non-flammable and explosive occasions.

(2) The concave-convex sealing surface consists of a concave surface and a convex surface, this sealing surface gasket is easy to center, when compress it ,the gasket will not squeeze out.So it can be used for slightly higher pressure occasions.

(3) The tongue and groove sealing surface consists of a tenon and a groove surface, the gasket placed in the tank, will not be squeezed and moved, because the gasket is narrow, the gasket clamping force correspondingly smaller, its shortcomings is the complex of structure and manufacturing , replace the gasket is also more trouble. Generally used for flammable, explosive, toxic media and high pressure occasions.

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