Australian Pipeline Valve - Installation, Operation and Maintenance Manual
9
LUBRICATED PLUG VALVES - SAPM/SAPL
Plug valves can be used for throttling for limited periods as normally used for vent applications, by-pass,
blow down, kicker, equalisation, etc. If a plug valve is used for throttling for limited periods, then its
suggested to proceed as follows:
1) Open the plug slowly to allow media to travel through the valve (this should occur when then opening
angle is 20-30°)
2) Open the plug further to modulate the flow as required.
3) When throttling is no longer required continue to open until the valve is fully open. Leaving the valve in
the partially open (throttled) position for long periods may cause damage and reduce the life of the
seat.
Do not force valves that will not readily operate. Never stand downstream of a valve that is being opened
to atmosphere. To prevent operation of valves that are installed where unauthorised personnel can
interfere with them the valve should normally be locked with suitable locking device, have the wrench or
handwheel removed or be chained through the handwheel.
DURING OPERATION TAKE INTO ACCOUNT THE FOLLOWING WARNINGS:
a- Graphite/Graphoil packing and body gasket is very brittle, any impacting, twisting or bending should
be avoided.
b- The valve’s internal parts such as plug, stem, seating area, seals, gaskets shall be handled with care
avoiding scratches or surface damage.
c- All tools and equipment for handling the internal parts shall be soft coated.
d- Valves can be fitted with gaskets or seals in PTFE, Buna, Viton, etc. Hence high temperatures will
damage sealing components.
e- Never part open valve. Valve must be full open of full closed to avoid seat damage.
For all operations make reference to position number on part list of the applicable drawing listed.
2.1 MANUAL OPERATION
Valve adjustment is by clockwise turning of stem. Lever operated and gear operated valves have position
indicator to indicate open or closed (see figure 1 & 2). Plug Valves must not be used for throttling. Valve
must be full open or full closed.
Figure 1
Figure 2
