Type and function of flange gasket
Commonly used flange gaskets are divided into three main categories:
1. Non-Metallic gasket
A, Asbestos rubber gasket
Features: Good elasticity, high strength, good oil resistance, high temperature resistance, easy access. But asbestos products can cause cancer.
Scope of application: T≦260℃, pn≦2.0mpa (SH3401), T≦400℃, pn≦4.0MPa (gb/t539), used in water, air, nitrogen, acid, alkali, oil and other media conditions.
B. PTFE Coated Gasket
Scope of application: T=-180~200℃, pn≦4.0mpa, often used for low-temperature or clean-required occasions.
2. Half metal gasket
There are three kinds of spiral gasket, metal-clad gasket and flexible graphite Gasket
A, winding type gasket
Features: It is the most ideal, the most widely used gasket in the half metal gasket, its compression resilience is good, the strength is high, is advantageous to adapts the pressure and the temperature change, can maintain the good seal performance under the high temperature, the low temperature, the impact, the vibration and the variable load. Material: Winding Steel Belt: 20, 1cr13, 0cr18ni10ti, 0cr17ni12mo2 and other materials
Non-metallic Winding Tape: Special asbestos, flexible graphite tape, PTFE tape
B. iron-clad gasket
The sealing performance is not as good as the wound gasket, so it is often used in the heat exchanger to seal the flange connection of the first-class large diameter.
C, Flexible graphite composite gasket
Suitable for face, concave surface and tenon groove Flange
3. Metal Gasket
It is commonly used in high pressure grade flange to withstand higher sealing pressure. Commonly used metal gasket has flat cushion, octagonal cushion, oval cushion three kinds
Metal Flat gasket: Often with the convex table, concave table, tenon groove surface flange used together
Octagonal gaskets and oval gaskets: often used with ring groove flanges. Compared to the two, octagonal gasket processing is easy, so more
In general, the material of metal gasket should be used with flange material, and the hardness of gasket is lower than that of flange (not less than 30HB).
we have our own pipe fitting factory since 1998 ,which covers 100 acres. In 1998, we invested and set up a new flange factory. Up to now, we have a complete production system, and become a professional and competitive group in this field.