| Inject-sealant online leak sealing technology is to stop leak process by using the method of rebuilding sealing structure under pressure, temperature or online condition. It plays a significant role on maintenance of the pipeline systems. In the oil refining enterprises, with high temperature and pressure chymic medium condition, how to implement safe and effective seal online leak is a problem to be solved.In this thesis, different curing systems and the influences of phenolic resins, fillers and stabilizers on the properties of NBR were discussed. The results showed as following:(1) The comprehensive performances of Carrier sulfur vulcanization system, including the aging properties in the hot-air and3#oil resistance at125℃, were found better than those of the peroxide vulcanization system.(2) Among several kinds of phenolic resin,3138has the best reinforcement effect for NBR material, TH390has the worst. However, when they were used together, the obtained heat resistance or oil resistance of the materials decreased. The comprehensive performance of the materials can be improved by adding a small amount of epoxy resin.(3) Appropriately increasing the crosslink density led to the decrease of the elongation at break, while the heat ageing stability and oil resistance were improved.(4) Among the several kinds of fillers, zinc oxide had the best contribution to the thermal aging resistance; carbon black had the best contribution to the oil resistance.(5) In sulfur vulcanization system, HB stabilizer brought the best heat resistance and the resistance to3#oil.Furthermore, finite element analysis method was adopted in fixture design and the field tests were executed. The results revealed that:(1) The GB150of pressure vessels formula only satisfied the requirement of the fixture’s strength demand, but didn’t satisfy the requirement of online leak sealing fixture stiffness. Stiffness is more important than strength in fixture design.(2) Local sealing method should be adopted for dealing with large leak holes whenever possible in order to reduce the stress and deformation of fixture and bolt.(3) Deformation of bolt is the largest, so in fixture design deformation of bolt should be considered first.(4) The fixture was subjected to great forces and the clearance between the fixture and the sealing surface was changing while sealing a large equipment during a sealing process. Increasing the thickness of the fixture is a good method to increase its rigidity. It is more important to make up for the dynamic change of the clearance. |
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