Guide to Industrial Valve Repair and Maintenance

Repair and Maintenance of Ball Valve

• Verify that the bolts and nuts are tight, and tighten them if necessary. To achieve the torque that the manufacturer recommends, tighten the bolts. The bolts, nuts, and valve flanges will be harmed by excessive torque.
• lubrication. To avoid abrasion wear on the ball during valve closure and opening, lubricate the valve often. Additionally, lubrication increases the efficacy of the seal and makes the valve's action smoother and simpler.
• Regularly grind the valve seat and ball.In order to ensure a tight seal when the valve closes, grinding will assist smooth the ball and seat.
• Examine the inside of the valve by opening it. If worn out or damaged, replace or lap the seat and/or ball valve. Additionally, clear the inside of the valve of any debris that has adhered to the valve body.
• If any gaskets or seals are worn out or damaged, inspect them and replace them.

Troubleshooting ball valves

• The ball valve is hard to operate.
  • The valve was clogged with solids. To remove the solids, open the valve bonnet.
  • corrosion within the valve itself. Clear the valve's interior of any corrosion scales.
• External fluid leakage
  • The valve and pipe should be loosely connected. Tighten the bolts and nuts to the torque that the valve manufacturer recommends.
  • The body and bonnet have a loose connection. Fasten the nuts and bolts firmly.
  • worn-out gasket. Change the gasket.
  • excessive fluid pressure. Make that the valve manufacturer's specified fluid pressure level is met.
  Leakage of internal fluid
  • The seat is damaged. Lap the valve seat or replace it.
  • The valve seat has debris lodged on it. To remove the dirt, open the valve.
• It is difficult to open and close the valve.
  • The valve has foreign objects lodged in it. Remove such materials by opening the valve.
• Noisy operation
  • High speed of fluid. Lower the fluid's velocity.
  • Incorrect valve size. Change the valve out for one with a higher rating.

Repair and Maintenance of Check valve/non-return valve

• To eliminate any flaws, no matter how minor, that could prevent the valve from closing perfectly, grind the valve seat.
• Lubrication. When closing or opening for fluid flow, lubricate the movable disc hinge pin to minimize wear and friction.
• After using the gasket for a certain amount of time, check and replace it. Because of the pressure coming from the body-bonnet connecting nuts, the gasket is harmed by prolonged use.
• Lap or replace the valve seat. The seat assists to create a tight seal between the disc and the body; if it is worn out or damaged, backflow or leakage will happen.
• Tighten the fasteners that hold the body and bonnet together to stop fluid from leaking.
• To stop fluid from leaking at the joint, tighten the nuts holding the valve to the pipe.

Troubleshooting check valve

• The valve disk does not open.
  • The direction of the valve's installation was incorrect. Install the valve in accordance with the manufacturer's instructions or so that the fluid flow corresponds with the arrow on the valve body.
  • There is little suction pressure. To generate a greater force capable of forcing the valve disc to open, raise the fluid flow pressure.
  • The downstream valve is shut off. The downstream valve should be opened.
• Reverse fluid flow
  • The disc is unable to close. Remove any foreign objects preventing the disc from returning to the valve seat by opening the valve.
  • worn-out valve seat. Lap the valve seat or replace it.
  • The valve seat has debris on it. After removing the bonnet and clearing the debris, open the valve.
• Fluid leakage
  • worn-out gasket. Change the gasket.
  • loose link. The bolts and nuts that link the valve body to the pipe and the valve body to the bonnet should be tightened. Excessive tightening, however, might harm the valve flanges, bolts, nuts, and gasket.
• The valve vibrates while in use.
  • high speed of fluid. Utilize the valve at the flow rate that the check valve manufacturer recommends.

Repair and Maintenance of Gate Valve

• To prevent accidents, losses, and environmental harm, make sure the system is free of stress before beginning any repairs or maintenance.
• Lapping of the valve. To improve a tight seal when the valve closes, smooth down the valve seat and disc using a lapping machine. An extended length of use causes the valve to develop scales, which obstruct disc closure and thus cause fluid leakage. Additionally, the accumulation of these scales lowers fluid pressure.
• lubrication. To lessen wear and friction and to make opening and closing the gate valve easier, lubricate the stem threads and stem nut. Apply lubricant with a grease gun.
• Every month or as the manufacturer advises, adjust the valve packing.
• Cleaning. To avoid fluid blockage, open the gate valve bonnet component and clean the valve seat, disc, and entry and exit ports.
• As advised by the gate valve manufacturer, tighten the nuts and bolts on the bonnet-body.
• If the fluid flow is not successfully stopped, replace the disk (the part that stops it). In order to access the valve inside and replace the disc, the valve bonnet must be opened.

Troubleshooting gate valves

• Leakage through the valve-pipe connection.
  1. Worn-out seals/gasket. Replace the seals/gasket.
  2. Bolt and nut connections are loose. Fasten the nuts and bolts firmly.
  3. excessive fluid pressure. Make sure the fluid pressure is at the manufacturer's suggested level for the gate valve.
• Leakage through the bonnet-body connection.
  1. Loose bolts and nuts. Tighten the bolts and nuts.
  2. Worn-out seals/gaskets. Replace the gaskets/seals.
• The valve is hard to operate.
  1. The valve stem or the valve itself contain blocked materials. Remove these materials by disassembling the valve.
  2. The valve stem has a curve. Put the stem back in place.
  3. Extremely tight packing. Loosen the packing.
• No fluid flows through the valve
  1. There is a blockage in the valve. Remove any extraneous materials from the valve by disassembling it.
  2. gate that is worn out. Change the gate.

Repair and Maintenance of Globe Valve

• grinding of the valve. Regular valve grinding will assist achieve a dense, even surface.A grinding machine is used to carry out the grinding process. Perfect and tight seals are made possible by this process, which smoothes seats and seals.
• Regular lubrication of the valve stem can assist minimize wear and improve smooth operation without requiring a lot of torque to open or close.
• To avoid blockage, open the globe valve bonnet and remove any scales or residue that may have accumulated inside the valve body and bonnet. Additionally, take advantage of this opportunity to check the valve seat and disc and replace them if necessary.
• To prevent leaks, replace the gland packing as advised by the globe valve manufacturer or after a specific amount of use.
• Inspect and replace the seals and O-rings after disassembling the globe valve.
• Replace the corroded nuts and bolts on the pipe-body and bonnet connections. Tight connections will be guaranteed by new bolts and nuts, preventing leaks and, consequently, fluid losses and environmental harm.
• Use cleaning chemicals to remove any buildup on the valve body.

Troubleshooting globe valve

• Fluid leakage through the bonnet
  1. nuts and bolts that are loose. As advised by the manufacturer, tighten the nuts and bolts on the bonnet.
  2. Worn-out bonnet gasket. Replace the gasket.
  3. High fluid pressure? Make sure the valve is operating at the manufacturer's suggested fluid pressure. Use a globe valve with a higher rating if not.
• Fluid leakage through the body-pipe connection
  • Loose connection. Tighten the bolts and nuts.
  • Worn-out gasket? Replace the gasket.
  • Extreme fluid pressure? Ensure the fluid pressure matches the value recommended by the manufacturer.
• The handwheel cannot open/close the liquid flow.
• • Extremely tightened packing. Loosen packing.
  • Worn-out stem threads. Replace the stem.
  • Foreign materials clog the valve disk. Open the valve and clean off the materials.
• The handwheel rotates but does not open/close the fluid flow.
• • Worn-out disc. Replace the disc.
  • Worn-out seat. Replace or Lap the valve seat.

Repair and Maintenance of Pressure Relief Valve

• Inspect the valve for corrosion. Replace corroded components of the valve.
• component cleaning for valves. Clear the valve's internal components of moisture and any objects that could hinder proper operation. Avoid vigorous cleaning, though, as this could harm the valve's sensitive components.
• Lap often.When the valve is shut, the lapping procedure will improve proper closure by assisting in the removal of scales from the valve seat and disc.
• Overused grease. Clean off overstayed grease since it accumulates dirt and or contaminates the valve.
• Put pressure on it. The performance of the pressure relief valve may be impacted by readjustment or tampering, as it is designed to function at a specific pressure. Thus, adjust the pressure to the manufacturer's suggested level.
• Seat. Replace or Lap the seat if it is causing fluid leakage.
• hat for rain. The valve is shielded from damage by this cap from ice, snow, rain, insects, dirt, debris, and pollution. If it is broken or missing, replace it.
• If the pressure relief valve's spring is exposed to chemicals, salty water, or industrial contaminants, it will eventually decay. To avoid malfunctions and mistakes, replace the spring if the coating chips or cracks.
• Examine weep holes and clear away any paint, debris, ice, or other foreign objects that might obstruct the valve's normal drainage.

Repair and Maintenance of Parallel slide valve

• Use a valve grinding machine to grind the valve seats and the two discs to smoothen them so that there is no fluid flow when the valve is stopped.
• Lubricate moving parts such as the yoke sleeve and stem to reduce wear and friction. Lubrication also helps to reduce the energy needed to open/close the valve. Also, lubricate actuator moving parts for actuated valves. Such components are drive sleeves for the motor actuator and sliding surfaces for the hydraulic/pneumatic actuator.
• Clean internal components of the valve, such as the stem, body, bonnet, and packing area. The cleaning helps to remove solids and contamination that may reduce fluid pressure or cause blockage of fluid flow.
• Tighten bolts and nuts connecting the body and bonnet and those connecting valves to the pipe. However, avoid excess torque on the nuts and bolts, as it will damage them. Also, check the valve actuator to ensure it is properly tightened.
• Adjust packing and stuffing box rings to prevent fluid leakage.

Troubleshooting parallel slide valve

• Leakage through the packing chamber
  • Loose bolts. Tighten the bolts evenly.
  • Insufficient packing. Increase the amount of packing rings.
  • The packing chamber is damaged, or the packing is worn-out. Replace with new packing.
  • Stem damaged. Replace/repair the stem as necessary.
• Leakage through the sealing
  • Worn-out seals. Replace seals.
  • Dirt accumulation on the sealing surface. Clean off the dirt. Excess fluid pressure. Reduce fluid pressure.
• The hand wheel is hard to operate
  • The packing is too tight. Adjust packing torque.
  • Worn out stem threads. Replace stem.
  • Dirt accumulation between the stem and gland. Remove the dirt.
• Fluid flow when the valve is closed
  • worn-out seats or disks.The disks and/or seats should be replaced or lapped.

Repair and Maintenance of Wedge valve

• Scales on the valve seat and disc can be removed with a lapping machine. By creating flat surfaces on the disc and seat, lapping helps eliminate flaws that obstruct ideal valve closing.
• adjusting the glands. To keep the seal intact and stop fluid leaks, adjust the gland on a regular basis.
• Lubricate the valve stem to facilitate opening and closing and lessen wear from friction.
• To stop leaks, check the stuffing box gasket and replace it if worn out or broken. Additionally, if the stuffing box nut is loose, tighten it.
• Regularly open the valve and clean the inside components. These parts include the body, bonnet, O-rings, and seals. Dirt, corrosion, contaminants, and any foreign elements that could subsequently create blockage are all helped to be removed by the cleaning. Additionally, inspect and replace the valve seat and disc if necessary.
• Examine the bonnet gasket and replace it if necessary. Particularly for hazardous fluids, a proper gasket will stop leaks that could result in losses, environmental harm, and consequent legal action.
• Check the torque of the bolts. Tighten the bolts if they are loose, but don't use too much torque as this could harm the nuts, bolts, and gasket.

Troubleshooting wedge valve

• Internal leakage
  • worn-out seat. Lap the valve seat or replace it.
  • Worn out seals/O-rings. Replace or Lap the O-rings and seals.
• External leakage
  • Loose bolts. Tighten bolts and nuts.
  • Worn out gasket. Replace the gasket.
  • Excess fluid pressure. Reduce the fluid pressure or use a higher-rated valve.
• Handwheel is hard to rotate
  • Dirt on the stem. Open the bonnet and clean off the dirt.
  • Damaged stem. Replace the stem.
• The valve does not open/close the fluid flow
  • Damaged stem. Replace the stem.
  • Worn out/damaged disc. Replace the disc.

Repair and Maintenance of Diaphragm valve

• Perform grinding operation using a lapping/grinding machine to smoothen out the valve diaphragm and weir for perfect closure.
• Cleaning. Clean the diaphragm regularly to prevent the buildup of dirt and contaminants to prevent damage to the diaphragm.
• Inspect the diaphragm and linings for failure and replace them if damaged.
• Check the body, seat, and bolts for tightness. If loose, tighten them to prevent fluid leakage.
• Check the body-bonnet bolts are tightly connected.
• Lubricate the valve stem to reduce the rate of wear and operating torque.

Troubleshooting diaphragm valve

• No fluid flow through the diaphragm valve
  1. The valve is closed. Open the valve.
  2. Pipe or strainer clogged. Check the filter or pipe for blockage.
• Leakage between the valve and the pipe
  1. Loose bolts. Tighten the bolts evenly.
  2. Worn out gasket or lining. Replace the gasket/lining.
  3. The valve and pipe are improperly centered. Centre the valve to the pipe.
• Difficult to operate the valve
  1. Dirt on the stem. Clean off the dirt.
  2. Worn out stem threads. Replace the stem.
  3. Foreign materials are trapped between the diaphragm and the body. Remove the foreign materials.
  4. High fluid pressure. Reduce the fluid pressure or use a higher-rated diaphragm valve.