Valve disassembly and reassembly – Flowserve Valtek Mark 10 Survivor Control Valves User Manual
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Valtek Mark 10 Survivor Control Valves FCD VLENIM0036-05 – 07/09
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5
Valve Disassembly
and Reassembly
5.1. Disassembling the Valve Body
To disassemble the valve body, refer to Figure 1 and proceed as follows:
WARNING:
c
Depressurize line to atmospheric pressure and drain all fluids before working on the
valve. Failure to do so can cause serious injury.
5.1.1.
If valve is air-to-close, proceed to step 5.1.3. If valve is air-to-open, put air under the
piston to lift the plug off the seat before taking the valve apart.
5.1.2.
Remove the bonnet flange bolting and lift the actuator, bonnet and plug out of the valve.
WARNING:
c
When lifting an actuator be aware that the center of gravity may be above the lifting
point. Therefore, support must be given to prevent the valve from rotating. Failure to do so can
cause serious injury to personnel and damage to the valve or nearby equipment.
CAUTION:
a
Care should be taken to lift the actuator and plug straight out of the body to avoid
damage to the plug and seat.
NOTE: Some Survivor valve designs require that the plug be removed by pulling through the bottom
of the valve. In these cases remove the bonnet, leaving the plug sitting on the seat ring while still
inside the body.
5.1.3.
At this point, the plug and seat sealing surfaces can be visually inspected for damage. If
the seat needs to be removed, install lifting lugs in the bonnet bolting holes and attach a
hoist to the body. Unbolt the end flanges and carefully lift the valve from the line.
WARNING:
c
When removing a two piece seat, the upper seat may remain in the valve body and
subsequently drop, causing harm to personnel, the seat ring, or nearby equipment. Care must be
taken to prevent the seat ring from dropping accidentally. If the seat ring sticks, pry the seat out
as the body lifts to prevent it from falling unexpectedly.
5.1.4.
If the seat ring is still in the valve body, remove it and inspect gasket surfaces on the seat
ring, bonnet and body, making sure they are clean and undamaged.