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Adjustments
The Enardo 450 and Enardo 550 Series pressure/
vacuum relief valves have wide range of pressure
and vacuum settings in units of oz./sq. in. or in. w.c.
Standard Fisher™ valve pallets installed alone has
minimum settings of 1/2 oz./sq.in. or 1 in. w.c. The
pallets are calibrated by the seal support located on
the bottom side of the pallet. The pallet's setting of
1/2 oz./sq.in. or 1 in. w.c. is etched into the support.
When a valve requires a setting higher than the
1/2 oz./sq. in. or 1 in. w.c. standard pallet setting,
use weights to increase the pallet's setting up to the
required setting.
Fisher weights also come in oz./sq. in. or in. w.c. The
individual setting of each weight is either etched or
imprinted into the weight. Emerson offers several
different sizes of pressure/vacuum relief valve. To
ensure that the right weight is placed on the right
pallet, take note that the weights and pallets that go
together have the same outside diameter. Standard
Fisher weights allow the user to stack in increments of
1/2 oz./sq. in. or 1/2 in. w.c.
Pressure/vacuum relief valve is shipped with
prepackaged weight kits to set the valve pressure
properly. The package labelled "PRESSURE" is for
the pallet in the pressure chamber, while the package
labelled "VACUUM" is for the pallet in the vacuum
chamber. All weights in these packages should
be installed. If one or neither of these packages is
included with your order, then they are not needed.
If the pressure and vacuum weights are mixed
together, sort and reorganize the weights.
When installing weights in the relief valve, check the
required setting on the tag attached to the relief valve.
Add weights to the pallet to achieve the required
setting. If the relief valve's setting is 6 oz./sq. in., add
weights with the total setting of 5-1/2 oz./sq. in. to the
valve since the pallet's setting alone is 1/2 oz./sq. in.
Hence, the valve pressure setting is the sum of the
settings of the pallet and the weights.
Enardo 450 and Enardo 550 Series
Relief Valve Maintenance
Make sure line is free of hazardous
vapors before installing or servicing
the valve. Use of non-sparking tools
is necessary if flammable vapors
are present.
Observe all applicable safety
requirements. Only qualified and trained
personnel shall maintain the valve in
hazardous locations.
Valves should be removed from the
location having a potentially explosive
atmosphere and taken to a safe location
for repair and maintenance.
Limited maintenance of the relief valve installed
on the tank is possible, provided that all necessary
safety precautions have been taken. To have the
optimum sealing performance of the Enardo 450 and
Enardo 550 Series, maintain the valve and use clean
and undamaged pallet seals and seats. To access
the pallets:
1. Loosen the fasteners on top of the valve and
remove the lid, hood or guide.
2. Remove any valve pallets and weights from the
unit. Take note of the proper chamber of the
pallets and weights.
3. Inspect the pallets for any damage and/or buildup.
Damaged pallets could not seal and move inside
the valve properly. If necessary, gently clean
the pallet and seal with a suitable solvent and
nonabrasive cloth. Never fold or crease the seal. If
the seal is damaged, replace it.
4. Remove any buildup on the weights.
5. Inspect the valve seats. The sealing surfaces
should be smooth and free of nicks or buildup. If
necessary, gently clean the seats with a suitable
solvent and nonabrasive cloth.
6. If lid is available on the valve, clean any buildup in
or around the guide hole located in the center of
the part.
7. Remove any blockage in the pressure or vacuum
screens that may impede proper flow of fluid.
▲
WARNING
7
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