Flowserve Serck Audco Twin Isolation Plug Valve - Manual (Page 9)

6 OPERATION
6.1 USE
Serck Audco TIPV plug valves are Double Block & Bleed valves designed to give bubble tight shut off.
TIPV plug valves have a ¼ turn operation (i.e. they have a 90 degree rotation of the plug in operating from
the fully open to the fully closed) and close in the clockwise direction when viewed from above the valve stem.
It is possible to see when the valve is open or closed by the position of a groove in the top of the stem, this
groove being in-line with the plug port.
Plug valves can be used for throttling for limited periods as typically done for applications such as vents, blow
down, by-pass, equalization, kicker etc. If a TIPV is used for limited throttling, then it is suggested to use
1 plug for throttling and another one for isolation and proceed as follows: (1) open the isolating plug fully,
(2) open the throttling plug slowly until media starts going through the valve (this should happen when the
opening angle is 20-30°), (3) modulate the flow by opening further the plug as required, (4) when throttling
is not required anymore continue to open until the valve is fully open. It is not good practice to leave a plug
valve in the partially open (throttled) position for long periods as this may cause damage and seat life
may be reduced.
Do not force valves that will not readily operate. Never stand downstream of a valve that is being opened
to atmosphere. Valves that are installed where unauthorized personnel can interfere with them should
normally have the wrench or handwheel removed, be locked with suitable locking devices, or be chained
through the handwheel to prevent operation.
6.2 WRENCH OPERATION
Wrench operated valves have an arrow shaped position indicator fitted over the stem. The arrow
points in the direction that the plug port is aligned. When the arrow points across the line of the pipe,
the valve is closed. Similarly, if the wrench is removed the flats of the stem will also indicate the valve
position. The indicator should not be removed as it also functions as the open and close stop by
coming into contact with the stop pin adjacent to the stem.
To adjust the wrench tube position within the wrench head, remove the retaining screw, reposition the
wrench tube, and then refit the retaining screw, and secure the wrench assembly to the stem by
screwing the retaining screw into the hole in the top of the stem.
When operating the valve the use of excessive side loading on the wrench should be avoided.
Serck Audco wrenches are sized so that the force to operate the valve should be 100 pounds
maximum at the end of the wrench.
6.3 GEARBOX OPERATION
All worm gear boxes supplied by Serck Audco have visible arrow type position indicators on top of the
gear housing. ‘OPEN’ and ‘SHUT’ positions are cast on top of the gear housing. The position indicator
arrow points to these at the fully opened and closed positions.
Secure the gearbox handwheel to the gearbox input shaft by the pin, or by the key and the retaining
screw. Ensure that the close direction indicator is visible on the end of the input shaft, and that the
retaining screw is tightened down. It is also recommended that the gear unit stops be checked to
ensure correct plug port alignment.
9 flowserve.com
Serck Audco TIPV Twin Isolation Plug Valve FCD - SRENIM0005-04 (A4) – 02/14