4
IOM-3600
V. MAINTENANCE
Tank or system protection is the primary function
of the weight loaded Vacuum Relief Vent. As a
safety device, it is very important that maintenance/
inspection be done on a regular interval. Maintenance
should only be done by a qualified technician. Valve
Concepts recommends that all service be performed
at the factory or a factory authorized repair center.
For information on repair centers in your area,
please contact factory.
Maintenance procedures hereinafter are based
upon removal of the relief vent unit from the tank
where installed.
Owner should refer to Owner’s procedures for re-
mov al, handling and cleaning of non re us able parts,
i.e. gaskets, suitable sol vents, etc.
To Dis-assemble:
Remove cap screws (10), cover
(8) and the TFE tape / rope seal (34).
Inspect cover for corrosion, damage, or product
build up. Clean with a suitable solvent, replace as
necessary.
NOTE:
During re-assembly, install new TFE tape /
rope (34).
Remove pallet assembly, including any loading
weights (28) that may be on the pallet (26).
Clean and inspect pallet assembly. Inspect the
diaphragms (25) and replace if necessary.
To Replace Diaphragm:
Secure stem assembly
(30) in a soft-jawed vise with short, threaded end up.
Remove washer and nut (14).
Lift up to remove diaphragm retainer (24) and
diaphragm (25). Clean stem assembly and
diaphragm retainer with a suitable solvent, replace
as necessary.
NOTE:
Before re-assembly, apply
TFE paste to threads of the stem and around center
hole on the pallet (26).
Install new diaphragm (25). Re-install diaphragm
retainer (24) and washer, secure nut (14) tight on
stem.
Inspect and clean seat ring (16).
NOTE:
FRP seat
surfaces are integral inside the body.
Check seat
surface for any nicks, corrosion, pitting or product
build up. Seat surface must be clean and smooth for
vent to perform properly.
To Remove Seat Ring:
Make a match mark between
the flange (1) and the upper body (13). Rotate cap
screws (15) CCW and remove. Remove guides (29).
(Use the slot on top of the guides and rotate CCW to
remove.) Mark the location of each guide on the seat
ring (16) flange for reference at re-assembly.
SECTION V
CAUTION
The pipeaway body (13) is no longer fastened securely
to the flange (1) and could fall and cause severe per-
sonal injury and material damage.
Lift up to remove seat ring (16) and TFE tape / rope
seal (34.1). Inspect guides (29) and inside of the
body cavity for any corrosion or product build up.
Clean all parts as necessary.
To Remove Pipeaway Tape Seals:
Separate
pipeaway upper body (13) from flange (1). Remove
TFE tape seals (34.1 & 34.2) and clean sealing
surface of both parts. Place new TFE tape seals
(34.1 & 34.2) in grooves on flange (1) face. See
Figure 8.
Using match marks align upper body with flange
and lower pipeaway body on flange, resting on tape
seals.
Place new seat ring TFE tape seal (34.1) in groove
in upper body (13). See Figure 8
Using match marks align seat ring (16) with body
and re-position seat ring back in body, resting on
tape seal.
Re-install pallet guides (29) around the seat ring as
previously marked. Install cap screws (15) - apply
15 ft.-lbs. (20.3 Nm) torque to tighten.
Place pallet stem assembly on seat ring (16).