12-1
Valtek Metal Bellows
Seal Valves
Rev. 6/97 Valtek No. 49022
GENERAL INFORMATION
The following instructions are designed to assist in
disassembling, reassembling and troubleshooting
Valtek valves equipped with a metal bellows seal.
Product users and maintenance personnel should thor-
oughly review this bulletin in conjunction with Mainte-
nance Instructions 1 (Mark One and Two Control
Valves) before installing, operating or performing any
maintenance on the valve.
This publication does not contain information on Valtek
positioners. Refer to the appropriate Maintenance
Instructions for installing, maintaining, troubleshooting,
calibrating, and operating Valtek positioners.
Three styles of metal bellows seal exist: Guardian,
Guardian II and Formed. Guardian II and Formed
bellows are constructed of flat material, which is rolled
into a tube and then seam welded. The walls of the tube
are then mechanically formed into convolutions.
Guardian bellows are constructed from a series of
matched pairs of metal discs that are welded together.
To avoid possible injury to personnel or dam-
age to valve parts, WARNING and CAUTION
notes must be strictly adhered to. Modifying
this product, substituting non-factory or infe-
rior parts, or using maintenance procedures
other than outlined could drastically affect per-
formance and be hazardous to personnel and
equipment, and may void existing warranties.
GUARDIAN METAL BELLOWS SEAL
Disassembling Guardian Metal Bellows
Seal
To disassemble the Guardian metal bellows seal, refer
to Figure 1 and proceed as follows:
WARNING: Since toxic or hazardous materials may
be present, depressurize the line to atmospheric
pressure. Drain all process fluids and decontami-
nate the valve. Failure to do so can cause serious
personal injury. Keep hands, hair and clothing
away from moving valve parts at all times. Face and
eye protection should be worn; otherwise, serious
personal injury may occur.
1. Remove bonnet flange bolts and nuts.
2. Remove the entire actuator/bellows seal assembly,
bonnet and bonnet flange by lifting them straight
out of the body.
WARNING: The sleeve may stick to the bellows
seal and fall from the assembly during removal
of the actuator assembly from the body, which
could cause damage or possible injury. To
remove a sticking sleeve, lightly tap on the
sleeve while lifting the actuator assembly.
NOTE: Heavy assemblies may require a hoist. A
lifting ring is provided on most actuators for this
purpose; otherwise, lift by the yoke legs using lifting
straps and a hoist.
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