In pipeline valve used in a wide variety, different structure, it is the most easily damaged pipeline fittings, maintenance for each valve, shall be carried out according to the concrete structure, which USES in the pipeline valves, many varieties of different structure, it is the most easily damaged pipeline fittings, maintenance for each valve, shall be carried out according to the concrete structure.
1: for the maintenance of body and cover body and cover is the most outside the valve closed shell, to bear the pressure of medium, the additional force when operation, other parts of valve weight, as well as the joint flange or thread tension. Body and cover request has the certain strength and stiffness, their damage is mainly medium corrosion, erosion and mechanical damage caused by local defects, when wall thinning is caused by corrosion or erosion, and affects their strength and stiffness, cannot repair, should be replaced.
Overhaul, the body and cover should be in the water pressure strength test, water, compressed air, kerosene or other medium to test its rigor. The defects of the body and bonnet generally adopt the method of repair welding, depending on the material selects the corresponding electrode and welding procedure. Before welding repair defective metal should be cleaned, still should inspect and repair after repair welding, and eliminating stress.
2: packing room equipment packing room overhaul repair and stuffing box including packing replacement parts inspection. When choosing packing, using conditions and the situation of medium must be considered. In general, oil cutting asbestos packing is suitable for a certain temperature of air, steam, water and heavy oil products. Graphite asbestos packing can be used for high temperature and high pressure conditions, especially in the clip has a steel wire of the graphite asbestos packing better compression resistance. High temperature and medium temperature change frequently used asbestos leaded packing. Strong corrosive medium available invasion ptfe asbestos packing or ptfe braid