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Some customers bought seals and looked at better quality seals, but lost the seal effect. What caused it?
: There are three main reasons for seal failure :
1.The sealing surface is opened
85％的密封失效不是因磨损造成，而是在磨损前就已泄漏了。 When repairing mechanical seals, 85% of seal failures are not caused by wear, but they leak before they wear.
“砂轮”会损坏硬环表面。 As soon as the sealing surface is opened, the solid particles in the medium enter the sealing surface under the action of liquid pressure. After the sealing surface is closed, these solid particles are embedded in the surface of the soft ring (usually the right ink ring), which actually becomes a " "Grinding wheels" can damage hard ring surfaces.
Because the moving ring or rubber ring is fastened on the shaft (shaft sleeve), when the shaft moves in series, the moving ring cannot fit in time, and the sealing surface is opened, and the sealing surface lags behind, so that solid particles enter the sealing surface. .
At the same time, there are solid particles between the shaft (shaft sleeve) and the sliding parts, which affect the sliding of the rubber ring or the moving ring (relative to the dynamic sealing point, common failure). In addition, the medium will also generate crystals in the friction parts of the rubber ring and the shaft (shaft sleeve), and solid substances will also be stored in the spring, which will open the sealing surface.
、 过热 2. Overheating
Because the sealing surface will generate heat, the temperature of the rubber ring should be lower than the design specification. 216℃，丁晴橡胶的使用温度为162℃，虽然它们都能承受较高的温度，但因密封面产生的热较高，所以橡胶圈有继续硫化的危险，最终失去弹性而泄漏。 The operating temperature of fluororubber and polytetrafluoroethylene is 216 ° C, and the operating temperature of nitrile rubber is 162 ° C. Although they can withstand higher temperatures, the heat generated by the sealing surface is higher, so the rubber ring continues to vulcanize The danger of eventually losing elasticity and leaking. (The cold zone is considered to be cold and brittle.) The heat will cause the medium to crystallize between the sealing surfaces, such as carbon, causing the sliding parts to be stuck and the sealing surfaces to be condensed. And some polymers are coked due to overheating, some fluids lose their lubrication due to overheating and even flash fire.
In addition to changing the condition of the medium, overheating will also exacerbate its corrosion rate. Causes the deformation of metal parts, cracks on the alloy surface, and cracks in some coatings. The design should use a balanced mechanical seal to reduce the specific pressure and prevent overheating.
、 超差 3 , out of tolerance
Correct assembly tolerances are necessary for the installation of mechanical seals. The shaft (sleeve) must have the appropriate surface roughness and correct dimensions, but manufacturers rarely provide tolerance data, which are critical for installation. of. The dimensional accuracy, shape and position tolerances of mechanical seals must meet the requirements of the drawings, and excessive tolerances will cause the seals to fail prematurely.
Therefore, these three main factors determine whether the seal will fail. We must also pay attention to our design and installation. 0.01mm，欢迎咨询。 Our Haisheng Rubber carmenfan.com has a professional engineer team to design rubber seals for you. The minimum tolerance can reach 0.01mm. Welcome to consult.
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