Mechanical seal spring and bellows material and selection.(HY-industry technical centre)
Mechanically sealed elastic elements are springs and metal bellows. They are spring force loading components, to ensure that the sealing surface is well bonded and automatically compensated after the end face is worn. It requires high material strength, high elastic limit, fatigue resistance, corrosion resistance and high temperature and low temperature, so that it is sealed in the medium. Long-term work, does not reduce or lose the original flexibility.
The Mechanical seal spring for pump mechanical seals are mostly made of 4Cr13, 1Cr18Ni9Ti (304 type) and 1Cr18Ni12Mo12Ti (316 type). In corrosive weak medium, carbon spring steel and phosphor bronze spring can also be used well in seawater and oil media. 60Si2Mn and 65Mn carbon spring steels are used in non-corrosive media at room temperature. 50CrV is used in high temperature oil pumps. 3Cr13, 4Cr14 chrome steel spring steel is suitable for weak corrosive medium; 1Cr18Ni9Ti and other stainless steel spring steel is used in dilute nitric acid. For highly corrosive media, corrosion-resistant alloys (such as high-nickel-chromium alloys) or spring-loaded polytetrafluoroethylene (PTFE) covers or PTFE coated to protect the spring from media corrosion.
The bellows material is metal, plastic and rubber. The material of the metal bellows can be austenitic stainless steel, martensitic stainless steel, precipitation hardening stainless steel (17-4PH), high nickel copper alloy (Monel), heat resistant high nickel alloy (Inconel), corrosion resistant high temperature nickel chrome Alloy (Hastelloy B and C) and phosphor bronze. OCr18Ni9Ti and 1Cr18Ni9Ti stainless steel are also used.