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TO REPLACE STEM PACKING 300-400 Series Valves
Close valves and drain fluid. Disengage packing gland nut and pull packing gland out of
stuffing box. Remove old packing and insert new packing. Put the packing gland and
packing gland nut into position and tighten the nut. The gland nut should be tightened
enough to stop leakage around the stem without causing excessive binding of stem during
operation.
TO REPLACE VALVE SEAT 400 Series Valves
Close valves and drain fluid, disengage sleeve nut from valve body and remove stem,
sleeve, sleeve nut, gland, gland nut as a unit from the valve. Using a standard 5/8” socket
wrench remove seat. Before replacing seat apply lubricant (Molykote “G” or equivalent) to
the threads to prevent seizure of metals. The seat is then replaced and tightened well to
prevent leakage. Replace the stem unit in the valve body and tighten the sleeve unit.
WARNING: During system shut down, it is best to leave shut off valves open, the
equipment then cools and depressurizes along with the system. Keeping
valves closed during shut down can trap high pressure liquid in the valves.
COMMISIONING
It is important to commission a gauge glass equipped with safety ball check valves properly
to avoid false level indications. If the valves are opened too quickly, the ball checks will
isolate the gauge before the level can equalize with that of the vessel.
Step 1: Open the top isolation valve by rotating the valve handle counterclockwise 1/4
to 1/2 turn.
Step 2: Repeat step one for the bottom isolation valve.
Step 3: Visually observe the level in the gauge and allow to reach equilibrium.
Step 4: Open the top valve 100% (until the handle no longer rotates).
Step 5: Repeat step four for the bottom valve.
MAINTENANCE
CAUTION: Prior to any disassembly of valves, first be sure that the valves are relieved of
all internal pressure, and temperature is ambient, and has been drained and /
or purged of any fluids. Failure to do this may result in a sudden release of
pressure and / or physical injury to personnel.
CAUTION: When the gauge fails causing the ball checks to seat, closing the valve will
allow fluid to flow from the vessel during that period when the pin pushes the
ball off its seat and before the stem has contacted seat, the operator could be
hurt if not realizing what is happening or fires could result if hazardous liquids
are involved.
16633 Foltz Parkway, Strongsville, OH 44149
Tel 800-992-2843 www.ernstflow.com info@ernstflow.com
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