First, the valve body leakage:     the reason: 1. The valve body has blisters or cracks ; 2. The valve body is cracked during repair welding     deal with: 1. Polish the suspected crack and etch it with 4% nitric acid solution. If there is crack, it can be displayed ; 2. Excavation treatment of the crack.     Second, the valve stem and its mating thread are damaged or the stem tip is broken and the stem is bent :     the reason: 1. Improper operation, excessive force on the switch, failure of the limit device, and over-torque protection. ; 2. The thread is too loose or too tight ; 3. Too many operations and long service life     deal with: 1. Improve the operation, the force is too large ; check the limit device and check the over-torque protection device ; 2. Select the appropriate material and the assembly tolerances meet the requirements ; 3. Replacement of spare parts     Third, the bonnet combined surface leakage: Reason: 1. The bolt tightening force is not enough or tightly biased ; 2. The gasket does not meet the requirements or the gasket is damaged ; 3. The joint surface is defective     deal with: 1. Retighten the bolts or make the door flange flanges consistent ; 2. Replace the gasket ; 3. Disassemble the door cover sealing surface     Fourth, the valve leakage:     the reason: 1. Closed is not strict ; 2. Joint surface damage ; 3. The gap between the valve core and the valve stem is too large, causing the valve core to sag or contact poorly ; 4. Poor sealing material or valve cartridge jam.     deal with: 1. Improve the operation, re-open or close ; 2. The valve is disassembled, and the sealing surface of the valve core and the valve seat is re-ground ; 3. Adjust the gap between the valve plug and the stem or replace the valve flap ; 4. The valve is disintegrated to eliminate the jam ; 5. Re-replace or weld the seal ring     5. The valve core is separated from the valve stem, causing the switch to malfunction :     the reason: 1. improper repair ; 2. The joint between the valve core and the valve stem is corroded ; 3. The force of the switch is too large, causing the joint between the valve core and the valve stem to be damaged ; 4. The spool retaining washer is loose and the joint is worn.     deal with: 1. Pay attention to inspection during maintenance ; 2. Replace the door rod of corrosion resistant material ; 3. Operation is not strong switch, or can not continue to open the valve after full opening ; 4. Check and replace damaged spare parts     Sixth, the valve core and valve seat have cracks:     the reason: 1. The quality of the joint surface welding is poor ; 2. The temperature difference between the two sides of the valve is large:     Repair welding with cracks, heat treatment according to regulations, light and grind.     7. The valve stem does not move up or down or the switch does not move :     the reason: 1. When the cold state is closed, it is too tight to be swollen after being heated or too tight after being fully opened ; 2. The packing is pressed too tightly ; 3. The valve stem clearance is too small to swell ; 4. The valve stem and the nut are too tightly matched, or the threaded fastener is damaged ; 5. Packing gland pressure deviation ; 6. The door stem is bent ; 7. The medium temperature is too high, the lubrication is poor, and the valve stem is seriously rusted.     deal with: 1. After heating the valve body, slowly test it with force or open it tightly and then close it slightly ; 2. After a little loose packing, try to open ; 3. Appropriately increase the valve stem clearance ; 4. Replace the valve stem and the nut ; 5. Re-adjust the packing gland bolts ; 6. Straighten the door lever or replace it ; 7. The door rod uses pure graphite powder as a lubricant     Eight, filler leakage :     the reason: 1. The filler material is incorrect ; 2. The packing gland is not pressed or biased ; 3. The method of adding packing is wrong ; 4. Stem surface damage     deal with: 1. Correct selection of fillers ; 2. Check and adjust the packing gland to prevent pressure deviation ; 3. Add packing according to the correct method ; 4. Repair or replace the valve stem three precision valve technology department provides Small Home Dehumidifier,Dehumidifier For Home,Intelligent Operation Dehumidifier,Industrial Air Dehumidifier Guangdong Widinlsa International Co.Ltd , https://www.widinlsamachine.com