Valve Disassembly And Reassembly - Flowserve Valtek Mark 100 User Instructions

Valtek ® Control Products Mark 100
6
Valve disassembly
and reassembly
6.1 Disassembling the body
To disassemble the valve body, refer to Figures 1 and 2, then
proceed as follows:
c
WARNING: Depressurize line to atmospheric pressure
and drain all fluids before working on the valve. Failure
to do so can cause serious injury.
1. Fully retract the plug until the stem clamp indicator points to
the open position.
2. Remove the bonnet flange bolting and lift the actuator,
bonnet and plug out of the valve body.
c
WARNING: Danger exists in removing the actuator,
bonnet and plug, especially if PTFE plug seals are used.
The sleeve may stick to the plug and fall during disas-
sembly, causing possible serious injury and damage
to the valve or nearby equipment. If sleeve is observed
sticking to the plug, steps 3 to 5 should be consulted.
a
CAUTION: Heavy actuators may require a hoist. Lift the
actuator with the yoke legs using a lifting strap and a
hoist. Great care should be taken to lift the actuator and
plug straight out of the body to avoid damage to the
plug and seat.
3. If the sleeve is observed sticking to the plug during
removal, fully extend the plug by applying air above the
piston, allowing the sleeve to remain in the body and the
bonnet to rise above the body.
4. In the gap between the top of the sleeve and the bottom of
the bonnet, place wooden blocking of equal thickness in at
least three places. The wooden blocks must not extend in
far enough that they interfere with plug movement. The plug
must be allowed to stroke up to the bonnet.
VAIOM000103-02 (EN/AQ) March 2020
and Mark 100SC Control Valves
™
5. By applying air below the piston, retract the plug until the
plug head is freed from the sleeve. Once the plug is free
from the sleeve, remove the plug and bonnet assembly from
the body.
6. Lift the sleeve out of the valve body using lifting points on
the top of the sleeve.
7. Remove cage, seat ring and gaskets from the valve body.
Figure 2: Cutaway drawing
8. Remove the pressure-balancing seals from the plug head.
9. Check to see the seating surfaces on both the seat ring
and plug are free of damage to ensure tight shutoff. Make
sure the gasket surfaces on the seat ring, bonnet and body
are clean and undamaged. Inspect the pressure-balanced
sleeve for scratches, wear or other damage.
Flowserve.com 10