7
MAINTENANCE (cont.)
7.2
STEM PACKING COMPOUND ADJUSTMENT
TIPV plug valves have an emergency stem packing compound injector unit. In the unlikely event of a TIPV
valve developing a stem leak, this fitting can be used to inject stem packing compound to re-seal the valve
stem. This can be safely done with the valve under pressure.
CAUTION:
Never unscrew the stem packing compound injector out of the TIPV valve body while the valve is
under pressure.
On threaded stem TIPV valves, the injected stem packing compound is the primary seal. On the ‘plain stem’
design with a bolted top gland, it is an emergency feature to back up the main stem packing rings.
CAUTION:
Never attempt to replace the stem packing rings in bolted gland TIPV, while the valve is under
pressure. In some models a quad ring/carrier is located under the gland. Consult Serck Audco Valves
Technical Sales for information on replacing these packing rings / quad rings and carriers.
Equipment Needed: Torque wrench and appropriate adaptor, Serck Audco stem packing compound
& Anti Seize 2667.
7.2.1
CONFIRM SUSPECTED STEM LEAKAGE by one of several methods:
• Wrench operated valves - stem leak on a liquid service will be visible as liquid flowing out from
where the stem protrudes from the body.
• Gas services - applying a detergent solution around the stem area will produce soap bubbles if the
stem is leaking. A bad leak may be heard as a hissing noise from the stem area.
• Gear operated valves - the area where the stem protrudes from the body is hidden by the gear
operator. Confirm stem leak by observing or applying a detergent solution around the relief valve in
the gear operator indicator plate, and the gear operator to valve body mounting area.
• Portable electronic hydrocarbon detectors - some are sensitive enough to detect stem leaks by
placing the probe adjacent to the stem.
7.2.2
THE STEM PACKING COMPOUND INJECTOR UNIT (SPCIU)
Consists of a hexagonal shaped (fitting) that is screwed into the valve body. Inside it is a check valve, and
stem packing compound is forced through it with a hexagon socket or headed screw that threads into the end
of the SPCIU.
Stem packing compound injectors are preloaded at the factory with sufficient Serck Audco stem
packing compound to re-energise the stem seal on installation if required.
7.2.3
INJECTING STEM PACKING COMPOUND
already in the SPCIU, , attach the allen key/hexagon socket to the torque wrench and locate on the hex.
Socket/headed screw in the centre of the, and rotate it clockwise until the recommended torque is reached.
Normally only 1-3 turns will be possible. The maximum recommended torque is dependent on the size of the
injecting hexagon screw or hexagon set screw. The torque values are:
- 3/8” UNC (M10) torque required 20lb.ft (27Nm)
- 1/2” UNC (M12) torque required 24lb.ft (34Nm)
- 3/4” UNC (M20) torque required 45lb.ft (60Nm)
NOTE:
It is important that the torque values are not exceeded to avoid damage or fracture to the stem packing
fitting. It should be noted that it is difficult to inject stem packing using a winding tool; it is preferable to use
a hexagon adaptor and a torque wrench. The injection screw must have a plain end. Operating the TIPV valve
during the injection of stem packing compound can assist in resealing the valve stem.
NOTE:
After Injection, clean the SPCIU fitting thoroughly and apply a rust preventative in order to prevent oxidation.
13
flowserve.com
Serck Audco TIPV Twin Isolation Plug Valve FCD - SRENIM0005-05 A4 – 02/17
