Kenco Engineering Flat Glass Gauge Valve - Manual (Page 3)

Page 3
MAINTENANCE
A.
Replace Stem Packing
Close valves and drain fluid. Disengage packing gland nut and pull the packing gland out of stuffing box. Remove
and discard old packing and insert new packing. Put the packing gland and packing gland nut into position, and
tighten the nut. The packing gland nut should be tightened enough to stop leakage around the stem without causing
excessive binding of the stem during operation.
B.
Replace Valve Seat (KHVR & KHVU Valves Only)
Close valves and drain fluid. Disengage the sleeve nut from the valve body and remove the stem, sleeve, sleeve
nut, packing gland, and packing gland nut as a unit from the valve (see page #4 for details). Use a standard 5/8”
socket wrench to remove the seat. Before replacing the seat, apply lubricant (Molykote “G” or equivalent) to the
threads to prevent seizure of the seat to the valve body. Tighten the seat well, to prevent leakage. Replace the
stem unit in the valve body and tighten the sleeve nut.
CAUTION – Prior to any disassembly of valves, first be sure that the valves are relieved of all internal
pressure, and that the 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 glass fails causing the ball checks to seat, closing the valve will allow fluid to
flow from the vessel during that period when the stem pin pushes the ball check off its seat and
before the stem has contacted the seat. Personnel can be injured if they don’t realize what is
happening. Fires could result if hazardous liquids are involved.
Packing Gland
Nut
Packing
Gland
Packing
WARNING –During system shutdown, it is best to leave shutoff valves open. The equipment then cools and
depressurizes along with the rest of the system. Keeping valves closed during shutdown can
trap high pressure liquid in the valves.