Installation and maintenance of ball valve

Ball valve installation:
  1. It must be confirmed that the pipeline and valve have been cleaned before operation.
  2. The actuator operation of the valve drives the stem to rotate according to the input signal: when the valve rotates 1 / 4 turn (900) in the forward direction, the valve is closed. When rotating 1 / 4 turn (900) in reverse, the valve opens.
  3. When the direction indicator arrow of the actuator is parallel to the pipeline, the valve opens; when the arrow is perpendicular to the pipeline, the valve closes.
Ball valve maintenance:

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

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

Remove the line pressure and leave the valve in the open position before servicing

Disconnect the power or air supply before maintenance

Before maintenance, disconnect the actuator from the bracket

  1. Packing locking

If the packing culvert is in the position of slight leakage, lock the stem nut.

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

  1. Replace seat and seal

A, dismantling

Leave the valve in the half open position, and flush the possible dangerous substances inside and outside the valve.

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

Remove the driving device – actuator, connecting bracket, lock washer, stem nut, butterfly spring piece, gnan, wear-resistant piece and stem packing in sequence.

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

Confirm that the ball is in the “off” position, which can be easily taken out of the valve body, and then remove the valve seat.

Push down the valve rod from the middle hole of the valve body until it is completely taken out, then take out the O-ring and packing ring.

Caution: use caution to avoid scratching the stem surface and the packing seal of the valve.

B. Reassembly

Clean and inspect the inspected parts. It is highly recommended to replace the seat and bonnet gasket and seal with spare parts package.

Assemble in reverse order.

Tighten the flange bolts crosswise with the specified torque.

Lock the nut with the specified torque.

After the actuator is installed, the valve core is driven to rotate the corresponding input signal by rotating the valve rod to make the valve open and close.

If possible, seal pressure test and performance test of the valve according to the standard after installing the pipeline.

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