Groth 1660A - Manual (Page 4)

Page 4 of 16
proper setting and testing procedure in the
appropriate pilot valve manual.
This manual is intended to provide
recommended procedures and practices for
installation, operation, and maintenance of the
Groth Series 1660A Pilot Operated Valve
(POV). Any standard procedures and
practices developed for a specific plant or
process may supersede this manual.
Although this manual cannot cover all possible
contingencies, following these guidelines
should provide safe, reliable pilot valve
performance.
Note: This manual covers the operation and
maintenance of the pressure/vacuum relief
valve; refer to the appropriate manual for the
pilot valve instructions.
For information not contained in this manual,
please contact:
Groth Corporation
13650 N. Promenade Blvd
Stafford, Texas 77477
281-295-6800 (phone)
281-295-6995 (fax)
www.grothcorp.com
SAFETY WARNINGS
This section is an overview of safety
guidelines that should be followed during the
installation, operation, and maintenance of
your valve. To understand the context of
these instructions and warnings, read and
understand this complete manual.
The purpose of a POV is to prevent excessive
pressure in a tank or process system. The
valve must be designed for the proper MAWP
and flow requirements of the system. Consult
API Standard 2000 for tank protection sizing
procedures. An improperly specified or
functioning relief valve may result in structural
damage to the tank or system.
In the event of an actuator diaphragm failure,
the valve will vent pressure to the
atmosphere, causing the pressure relief valve
to fail in the OPEN position. The valve will
function like a weight loaded valve under this
condition with a lower set point, and will
normally provide rated flow capacity. Consult
factory for any questions related to this over-
pressure condition.
POV relief pressure and blowdown are set at
the factory per purchase order specifications.
The set pressure and range of adjustment are
stamped on the pilot valve nameplate. Do not
attempt to readjust the set pressure beyond
the limit specified on the nameplate.
The pilot sense line is either 3/8" OD SS
tubing, or 1/2" NPT PVDF pipe. It must be
open and unobstructed to ensure that the pilot
"senses" actual tank pressure. For
applications where tank vapors may condense
or "solidify" in the sense tube or pilot valve, a
nitrogen purge may be required to prevent
internal obstruction. Consult the factory for
recommendations.
DO NOT attempt to remove the pilot valve
from the main valve without removing or
isolating the relief valve from the system.
ALTERNATIVE MEANS OF PRESSURE
RELIEF MUST BE PROVIDED WHEN THE
VALVE IS OUT OF SERVICE. After isolating
the relief valve, bleed all pressure from both
main and pilot valve before removing the
valve. Consult the pilot valve manual before
attempting to repair it. Both the pilot valve
and POV are exposed to process vapors.
Observe all plant procedures and Material
Safety Data Sheet recommendations for the
products in the system when inspecting,
adjusting or servicing the valves. Vents on
the body and spring bonnet of the pilot valve
must be clean and unobstructed for proper
and safe operation of the valve. These vents
should be inspected periodically, and cleaned
or replaced, if necessary.
INSPECTION AND STORAGE
The POV is packed and supported to prevent
damage or contamination during shipping. It
should be similarly protected during
subsequent handling and storage. Always
keep all ports plugged to prevent intrusion of
foreign materials. Before installation inspect
the unit visually. If there are indications of
physical damage or internal contamination,
the valve must be disassembled, cleaned and
inspected before installation. The spring
adjustment cap and blow down screw lock nut
may be "car sealed" to ensure that the factory
pressure setting has not been altered.
Inspect the valve for any sign of damage that
may have occurred in shipment and report this
to the carrier.