Teflon (PTFE) gasket is the main material of polytetrafluoroethylene, because it has a very good characteristics and is widely used in various industries, can also be based on different operating environments and other needs, add different substances as a filler , After a special process from processing. At present, PTFE Gasket is an integral part of the pipeline flange seal, the working principle of the gasket during the sealing process is through the external force lock gasket material to produce plastic (or elastic) deformation, thus filling the sealing surface on the bump Uneven position, completely cut off the leak channel, to achieve the purpose of sealing.
Standard type of PTFE Gasket:
Currently on the market a lot of types of gaskets, we are mainly based on the material and structure to divide the general category: ① non-metallic gasket (PTFE, asbestos rubber sheet, rubber, flexible graphite, cross-sectional shape are rectangular) , Metal pad (metal pad, triangular pad, ring pad, wave pad, lens pad, tooth pad, double cone ring, hollow O-ring, C-ring, etc.), ③ metal composite gasket Metal wound pad, metal pad)
If the classification from the seal of the words: "non-metallic gasket", "metal gasket" in the metal flat pad, ring pad, wave pad, tooth pad, lens pad, and "metal composite gasket" Forced seal, the rest are self-tight and semi-self-tight seal.
PTFE Gasket with high quality and poor quality difference
Teflon gasket standard and selection principle:
Proper use of gasket is the protection of the use of pipelines. When we choose PTFE Gasket, we should choose according to the physical properties of the medium, temperature, pressure, operating conditions, equipment size and the length of continuous operation cycle. The main basis is as follows:
▲ Selection of PTFE gasket Note:
① match the flange with the sealing surface in the form and size
② nominal pressure of flange and gasket
③ nominal diameter of flange and gasket
④ the nature of fluid medium
⑤ the temperature of the fluid medium
▲ choice of PTFE gasket to be considered factors:
① Is the rebound and compression performance good? Is it possible to accommodate pressure and temperature fluctuations?
② Can the plastic properties fit well with the sealing surface of the flange?
(3) For individual metal flanges (such as austenitic stainless acid-resistant steel) containing stress corrosion cracking, can the gasket material contain no excess impurities that cause corrosion (such as reasonable control of the chloride ion content of the gasket) To prevent corrosion of the flange)
④ whether it will contaminate the impurities (that is, sealing medium for drinking water, beer, drugs, plasma, etc.)
⑤ PTFE Gasket For certain seals of highly toxic chemicals, the gasket must have greater safety. On the piping system where the flammable liquid is delivered, the gasket can be controlled at the maximum operating temperature and maximum use for the flange Is the pressure within the limits?
⑥ high temperature, is not easy to soften, creep resistance is good enough? Is it easy to soften when the temperature is low and whether the amount of shrinkage is good enough?
⑦ processing performance okay? Is it easy to compact and install?
⑧ gasket to be easy to disassemble, can do not bonded flange sealing surface?
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