Instructions eh10000 - 06/10
10000 series Double Ported globe valves
3
5. Body Disassembly (Refer to
Figure 9)
Access to the internal components of the body should be
accomplished with the actuator removed. To remove the
actuator from the body, refer to the appropriate actuator
instruction er8788.
Prior to performing maintenance on the valve, isolate the valve,
vent the process pressure, shut off supply and signal air lines
to the actuator. In addition, it is recommended that the bonnet,
body and bottom flange be marked in relation to each other so
the same orientation can be maintained during reassembly.
A.
remove stem lock nuts and travel indicator if applicable.
B.
remove packing flanged nuts (2), packing flange (3), packing
follower (19) from the bonnet.
C.
remove body stud nuts (11) from around the bonnet and
bottom flange.
D.
remove bonnet (6) bottom flange (10) gaskets (13) and plug
and stem subassembly (9, 1 and 8) from the body.
Note: If a new body gasket (13) is not available, care must
be taken to preserve the old gasket for reuse. Spiral wound
flexitallic gaskets are standard in the 10000 Series design,
and it is recommended that a new gasket be installed each
time the valve is disassembled.
E.
remove packing (17) and packing spacer (18) from the bonnet.
F.
Inspect all parts for wear and service damage. If bushings
(14) must be removed from the bonnet or bottom flange, refer
to section 6.2. After determining the maintenance required,
proceed to the appropriate section of these instructions.
6. Maintenance / Repair
The purpose of this section is to assist maintenance personnel
by suggesting methods of component maintenance which is
largely dependent on the tools and machine shop equipment
available. each section should be read and understood before
proceeding.
6.1 Seat Ring Removal
Threaded seat rings (15 and 16) are installed tightly at the point
of manufacture and after years of service they are often difficult
to remove. To facilitate removal, seat ring wrenches can be
fabricated to engage the seat ring lugs and adapted to a shock
wrench (see figure 3). If the ring is exceptionally resistant to
removal the application of heat or penetrating oil should be
helpful.
Figure 3
When using heating devices, ensure that proper safety practices
are observed. such items as flammability and toxicity of
the controlled substance must be considered and proper
precautions taken.
6.2 Bushing Removal
The bushings (14) are press fit into the bonnet and bottom
flange, and do not normally require replacement. however,
should replacement be required, they can be pulled or machined
out. When machining the bushings out, care must be taken to
maintain proper dimensions and tolerances. These will be
furnished upon request.
6.3 Lapping Seats
lapping is the process of working the valve plug against the
seat ring with an abrasive to produce a close fit. When valve
leakage becomes excessive, lapping becomes necessary.
The plug and seat ring seating surfaces should be free of large
dents, scratches and the contact surfaces of the seats should
be as narrow as possible. This may require dressing both parts
in a lathe. Both surfaces make an angle of 30˚ with the axis of
the plug (see figure 4).
Figure 4
for the lapping operation, a good grade of fine grinding
compound is required. The compound would be mixed with a
small quantity of lubricant, such as graphite. This will slow the
cutting rate and prevent tearing of the seating surfaces. The
amount of lapping required depends on the materials, condition
of seating surfaces and accuracy of machining. If a short period
of lapping does not visibly improve seating there is usually no
