Valve daily maintenance methods: First, the valve body and bonnet leakage: ? the reason: Cast iron casting quality is not high, body and valve cover body with trachoma, loose tissue, slag and other defects? 2 day cold cracking; 3. Poor welding, there is slag, welding, stress cracks and other defects; 4. Cast iron valve damaged by heavy objects. Maintenance method: ? 1 to improve the quality of casting, installation in strict accordance with the provisions of the intensity test; ? 2. The temperature of 0 ° and 0 ° below the valve, should be heat or heat mixing, stop using the valve should exclude water? 3. The weld of valve body and bonnet consisting of welding shall be carried out according to the relevant welding operation rules and the flaw detection and strength test shall be carried out after welding; 4. Do not push the valve on the heavy objects, does not allow the use of hand hammer impact on cast iron and non-metallic valves, large diameter valve should be installed bracket. Second, the leak at the packing (the valve leakage, packing accounted for the largest proportion) ? the reason: ? 1. Filler use of wrong, intolerant media corrosion, impatience valve high pressure or vacuum, high temperature or low temperature use; ? 2. Packing is not installed, there is a small generation, poor spiral wound joints, such as tight loose under the flaws; 3. Filler over the use of aging, loss of elasticity? 4. Valve stem accuracy is not high, there are bending, corrosion, wear and other defects 5. Lack of packing, gland is not compressed; 6. Gland, bolts, and other parts damaged so that the gland can not be pressed; 7. Improper operation, excessive force, etc .;? 8. Gland skew, gland and the gap between the valve stem is too small or too large, resulting in stem wear and tear, packing damage. Maintenance method: ? 1. Should be selected according to working conditions filler material and type; ? 2. According to the relevant provisions of the correct installation of packing, packing should be pressed circle by ring, the joint should be 30 ℃ or 45 ℃; 3. Long service life, aging, damaged packing should be promptly replaced; 4. Stem bending, should be straightened after wear and tear, repair, serious damage should be promptly replaced; 5. Filler should be installed in accordance with the provisions of the number of turns, glands should be evenly symmetrical tight, pressure sleeve should be more than 5mm preload gap; 6. Damaged gland, bolts and other parts should be promptly repaired or replaced; 7. Should comply with operating procedures, in addition to the impact of the hand wheel, with normal speed operation; ? 8. Should be evenly symmetrical screwed gland bolts, gland and stem clearance is too small, it should be appropriate to increase the gap; Gland and stem gap is too large, should be replaced. Third, the sealing surface of the leak ? the reason: 1, sealing surface grinding uneven, can not form a tight line; 2, the stem and the closure of the connection at the top center of the heart vacant, not correct or wear; 3, the valve stem bending or improper assembly, so that the closure of the skew or not in every match; 4, sealing surface material quality improper selection or not according to the condition conditions of the valve? Maintenance method: 1, according to the conditions of the correct choice of materials and type of gasket; 2, carefully adjusted, smooth operation; 3, should be evenly and symmetrically threaded bolts, torque wrenches should be used when necessary, preload should meet the requirements, not too large or small. Flange and threaded connections should have some pre-tightening clearance; 4, Gasket assembly should meet every time, uniform force, the gasket is not allowed to overlap and use double shims; 5, static cover corrosion, damage processing, processing quality is not high, should be repaired, grinding, coloring inspection, the static sealing meet the relevant requirements; 6, install the gasket should pay attention to clean, sealing surface application of kerosene, gaskets should not be landing. Four, seal leakage at the junction? the reason: 1, ring rolling lax 2, the sealing ring and the body welding, welding quality is poor; 3, sealing ring thread, screws, pressure ring loosening; 4, the ring connection is corroded. Maintenance method: 1, sealing leakage at the rolling Department should be injected adhesive and then fixed rolling; 2, the seal should be re-soldered welding welding regaining norms. Welding Department can not be repaired when the original welding and processing should be cleared; 3, Remove the screws, pressure ring cleaning, replacement of damaged parts, grinding seal and the connection seat close to the surface, re-assembly. Corrosion damage larger components can be used welding, bonding and other methods of repair; 4, sealing ring connecting surface is corroded, available grinding, bonding and other methods of repair, repair can not be used when the seal should be replaced. Fifth, the closure off pieces produce leakage: ? the reason:? 1, poor operation, so that closing pieces stuck or over the top dead point, the junction damage broken; 2, the closure of the connection is not strong, loose and fall off; 3, the choice of connector material is wrong, can not withstand the corrosion of the medium and mechanical wear and tear. Maintenance method: 1, the correct operation, closing the valve can not force too much, open the valve can not exceed the top dead center, the valve fully open, the hand wheel should be reversed a little; 2, closing parts and valve stem should be firmly connected, threaded connections should be back parts; 3, the closing piece and the stem connection fasteners should withstand the erosion of the media, and have a certain degree of mechanical strength and wear resistance. ? More Keyword Search : Pump Valve Ps Foam Cutting Machine,Hot Wire Cnc Foam Cutting Machines,Foam Cutting Machine Cnc,Industrial Foam Cutting Machine haiyuanmachinery , https://www.hyfoambox.com