Application of pressure injectant sealing leakage in chemical plant was described combining the service experience in Yunnan Natural Gas Chemical Group Co.

The paper analyses the leaking reasons for the newly installed valves of the new HP steam drum, and describes the measures to plug the leak under pressure.

It introduces the leakage blocking with pressure on the high temperature and high pressure valve without affecting the normal operation of the producing plant with a successful example.

Some methods of leakage blocking with pressure are direct drilling,plugging with fixture,copper wire leakage blocking and belt of Steel leakage blocking.

The technique of under pressure inject-sealant leak sealing needs constant pressure of medium for a longer sealing.

Exploration and research of pressurized plugging-up technology prevention;

introduces basic principles,operating procedures and sealing agents types of conventional caulking by repairing welding method and recently often used non-stopping pressurized caulking technologies,and it compares both of them.