subject: Mechanical Seal In Some Of The Problems Encountered [print this page] In the manufacture of mechanical seals, we will find a lot of problems. Today I will focus on these issues together, as we answered their questions. Hope to help.
1. Sealing ring stress state is like?
Of sealing ring by force, the aim is to analyze the work of the state seal ring in the type of force, direction and size, calculated on this basis than the pressure face. Force status of sealing ring and the seal structure. A general view of the Mechanical seals ring of mechanical analysis of an example. Ring by the spring force with force, media pressure, and liquid pressure, in addition to the friction ring. Among these forces, spring force and the media pressure in the same direction, so that sealing surface closure, called the closing force. Liquid force to separate the sealing surface as opening force. The experiment confirmed that the friction force is small, it is to be ignored.
2. Seal faces in the distribution of film pressure?
Take an internal flow analysis of the Mechanical seals cracks in the film Friction pressure distribution. By doing a number of assumptions; two planes are parallel; surface roughness and roughness compared with the film thickness is very small, so their impact can be ignored. First of all, the pressure of the liquid film diameter Office, where the role of pressure by the media, apparently is numerically equal to medium pressure. ID Department to atmospheric pressure, the pressure value equal to zero. Defined boundary conditions, the pressure in the gap in how change it? By a large number of tests, it measured the pressure value of each point. Found the film pressure distribution, distribution and nature of the medium, while with the Mechanical seals faces and friction in the phase relationship between the state also. In the same experimental conditions, the viscosity of butane and other small (easily vaporized) in the medium, the pressure sealing surface of a concave parabolic distribution; for medium viscosity media, the pressure distribution is linear; for high viscosity medium (such as lubricating oil, etc.), the pressure distribution is convex parabolic.
3. What materials used under high pressure assisted sealing plan?
Above the general condition of several materials suitable for use only auxiliary seals. Under high pressure, especially high-pressure and high temperature exist, they are not competent, then had to use metal materials. According to different working conditions for the use of different metal materials. High pressure, metal "0" ring commonly used materials: Crl8Ni9, Crl8Nil2M02Ti, 1Crl8Ni9Ti and 1Crl8NillNb etc.; the triangular cross section shape of the metal ring is often used chromium steel, such as 0crl3 etc.; for some copper flat pad is to use more or aluminum pad. Under high pressure and temperature, the material strength and elastic modulus decreased significantly, should be heat-resistant alloy, such as Inconel alloy or Inconel First materials. In addition to the above mentioned sections with a single auxiliary sealing materials abroad, but also the Mechanical seals of composite materials. For example, the PTFE bag stainless steel, Teflon bag and rubber, good sealing effect due to use of great potential.
