2
IOM-5400
CAUTION
DO NOT attempt to remove the vent from the tank or
process vessel without
fi
rst bleeding all pressure from
the system. ALTERNATIVE MEANS OF PRESSURE
RELIEF MUST BE PROVIDED WHEN THE VENT IS OUT
OF SERVICE.
SECTION III
IV. SHIPPING, INSPECTION AND
STORAGE
The pressure relief vent is carefully packaged to
prevent damage or contamination during shipping.
Inspect the equipment when it is received and
report any damage to the carrier immediately. The
POVV should be stored in a clean environment with
all the protective flange covers in place to prevent
intrusion of foreign materials. If there are indications
of physical damage or internal contamination, the
valve may need to be disassembled, cleaned, and
inspected prior to installation.
Tank or system protection is the primary function of
the Pilot Operated Vent Valve (POVV). It must be
selected to meet the total pressure flow requirements
within the maximum allowable working pressure
of the system on which it is installed. Consult API
Standard 2000 for tank protection sizing procedures.
Improperly specified relief vents may result in
structural damage to the tank or system, and can
cause severe personal injury or death.
In the event of a diaphragm failure, the Model 5400
will vent pressure to the atmosphere causing the
pressure relief vent to fail in the OPEN position. The
vent will function like a weight loaded valve under
this condition with a lower set point. Consult the
factory for any questions related to this over-pressure
condition.
The 1/2” OD SST pilot valve sensing line must be
kept open and unobstructed to ensure that the pilot
“senses” the actual tank pressure. For applications
where tank vapors may condense or polymerize in
the sensing tubing or the pilot valve, a nitrogen purge
may be required to prevent internal obstruction of the
tube. Consult the factory for recommendations.
Lifting brackets may be provided on the main valve
for lifting and handling. To avoid damage to the
lower flange surface, rest the vent on soft, clean
gasket material until it is ready to be installed.
DO
NOT
store the POVV directly on the ground.
WARNING
Warning: Before beginning any relief vent inspection
or maintenance, carefully read and understand the
information in this manual. If there are any questions
concerning the information in this manual, please
contact the factory before proceeding.
CAUTION
DO NOT attempt to change pressure set point beyond
the limit specified on the nameplate.
SECTION IV
III. SAFETY WARNINGS
After isolating the relief vent, bleed all pressure
from both main and pilot valve before removing the
Model 5400 POVV.
NOTE:
Both the pilot valve and main valve are
exposed to the process vapors. Observe all
plant procedures and Material Safety Data Sheet
recommendations before inspecting, adjusting or
servicing any components.
The vent on the spring bonnet of the pilot must
be clean and unobstructed for proper and safe
operation of the valve.
