TDW PIG-SIG V, Operating And Maintenance Instructions Manual

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Section IV – Pipeline Under Pressure
3.0 Continued
3.2 Checking Operation of Tapping Valve
A. Ensure the valve will open and close properly.
Operate and visually check that the valve
completely opens and closes (Figure 4.42).
Depending on type of valve:
Ball Valves : ensure stops and indicators are
correctly set, or
Gate Valves : Count the number of turns required
to open and close the valve completely. Record
the number of turns on the Measurement Card
and measure the length of the stem above the
operating handle in the open (Figure 4.43) and
closed position (Figure 4.44). Take note of these
measurements.
Figure 4.42. Open and
Close Valve
Figure 4.43. Open
Position
Figure 4.44. Closed
Position
B. Leave the valve in the open position.
⚠ CAUTION
Do not use force when opening and
closing the valve. Use of force will
not improve the seal and can
damage the valve.