Manual
2
IOM-5200 
 CAUTION
DO NOT attempt to remove the vent from the tank or 
process vessel without  rst bleeding all pressure from 
the system. ALTERNATIVE MEANS OF PRESSURE 
RELIEF MUST BE PROVIDED WHEN THE VENT IS OUT 
OF SERVICE.
SECTION III
III. SAFETY WARNINGS:
IV. SHIPPING, INSPECTION AND
 STORAGE:
The POVV 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  ange 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  ow 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 speci ed 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 5200 
will vent pressure to the pipeaway connection causing 
the pressure relief valve to fail in the OPEN position.
The vent will now function like a weight loaded vent 
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.
After isolating the relief vent, bleed all pressure 
from both main and pilot valve before removing the 
Model 5200 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.
Lifting lugs may be provided on the main valve for 
lifting and handling. To avoid damage to the lower 
 ange surface, rest the vent on a soft clean gasket 
material until it is ready to be installed. DO NOT 
store the POVV directly on the ground.
Make sure that any loading weights that might have 
been shipped separately, to protect the vent during 
shipping, are accounted for and stored with the vent.  
These weights when required, will be installed during 
installation,at installation.
 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 or an authorized repair center 
before proceeding. 
 CAUTION
 DO NOT attempt to change pressure set point beyond 
the limit speci ed on the nameplate.. 
SECTION IV










