20

2020

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02

Ball valve installation and maintenance

Author:


Ball valve installation: Make sure that pipes and valves have been cleaned before operation. The actuator operation of the valve drives the valve stem to rotate based on the size of the input signal: when it rotates 1/4 turn (900) in the forward direction, the valve is closed. When rotated 1/4 turn (900) in the opposite direction, the valve opens. When the actuator direction indicator arrow is parallel to the pipeline, the valve is open; when the arrow is perpendicular to the pipeline, the valve is closed.

Ball valve installation:

  1. Make sure that pipes and valves have been cleaned before operation.

  2. The actuator operation of the valve drives the valve stem to rotate based on the size of the input signal: when it rotates 1/4 turn (900) in the forward direction, the valve is closed. When rotated 1/4 turn (900) in the opposite direction, the valve opens.

  3. When the actuator direction indicator arrow is parallel to the pipeline, the valve is open; when the arrow is perpendicular to the pipeline, the valve is closed.

     

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    Ball valve repair:

    Having a longer service life and maintenance-free time will depend on several factors: normal operating conditions, maintaining a harmonious temperature /pressure ratio, and reasonable corrosion data

    Note: When the ball valve is closed, the fluid pressure in the valve body still exists.

    Before servicing, remove line pressure and leave valve in open position

    Before servicing, disconnect the power or air supply

    Before maintenance, detach the actuator from the bracket

  1. Packing lock

    If the packing culvert is slightly leaking, the valve stem nut must be tightened.

    Note: Do not lock, usually 1/4 ring to 1 ring, the leakage will stop.

  2. Replace valve seats and seals

  1. Disassembly

    Leave the valve in the half-open position to flush any hazardous materials that may be inside and outside the valve.

    Close the ball valve, remove the bolts and nuts from the flanges on both sides, and completely remove the valve from the pipe.

    Disassemble the driving device in sequence - actuator, connecting bracket, anti-loosening washer, stem nut, butterfly shrapnel, glamor, wear-resistant sheet, and stem packing.

    Remove the body cover connecting bolts and nuts, separate the valve cover from the valve body, and remove the valve cover gasket.

    Make sure the valve ball is in the "off" position, which will make it easier to remove it from the valve body, and then remove the valve seat.

    Gently push the valve stem downward through the middle hole of the valve body until it is completely removed, and then remove the O-ring and packing ring.

    NOTE: Use caution to avoid scratching the stem surface and the valve's packing seal.

  2. reassemble

    Clean and inspect parts of the inspected parts, and it is highly recommended to replace valve seat and bonnet gaskets and seals with spare parts kits.

    Assemble in the reverse order of disassembly and assembly.

    Cross-tighten the flange bolts with the specified torque.

    Use the specified torque to tighten the nut.

    After installing the actuator, the valve core is driven by rotating the valve stem to rotate according to the corresponding input signal, so that the valve reaches the open and closed positions.

    If possible, after installing the pipeline, perform a sealing pressure test and performance test on the valve according to standards.