Doc. #: A-718C, Rev. 1
Page 12 of 36
3.0 Operating Instructions
3.1
Valve Operation Notes and Precautions
NOTE:
Operation of the valve must conform with all applicable CTC, AAR, DOT specifications
(Parts 173.31, 174.67, etc.), other governmental bodies, and the operating instructions of your
company.
3.1.1 Bear in mind with the Midland angle valve that it will seal completely with much less torque than a metal-
to-metal seated valve. It should close with the same approximate torqueing as with a faucet on a wash
basin. Turn the hand wheel clockwise to close the valve; turn the hand wheel counterclockwise to open the
valve.
CAUTION
:
Do not apply a “cheater” or handle extension to the hand wheel
. Excessive force
will shear through the valve’s Teflon
®
seal, making it difficult or impossible to close off. If the valve
is leaking at the seat inside the valve and you cannot stop it by a firm closing (by hand) of the hand
wheel, inform your supervisor that the valve is defective and must be removed for reworking.
3.1.2 Examine the pipe plug. Be sure its threads are clean, free from corrosion and not worn or crossed. Also,
examine the threads on the side port to see that they are in good operating condition.
3.1.3 This valve has an adjustable packing gland. Use a 1-1/16" wrench to tighten the packing screw (item
8
). In
the event of a packing leak,
ensure the packing screw is torqued to a minimum of 30 ft-lb. T
ighten the
packing screw in 1/4-turn increments until the leak stops
, then turn an additional 1/4 turn
.
Unnecessary overtightening of the packing screw will cause excessive frictional drag on the valve stem.
Figure 3-1 Pipe Plug
Figure 3-2 Tighten Packing Screw
