Groth 1402 - Manual (Page 3)

1402revb.doc 2
If the 1402 pilot is used to control a single
acting actuator, the “lower dome” port is
plugged and the pilot controls pressure to
the upper actuator chamber only.
The pilot must be maintained by a
knowledgeable valve technician. It
should only be assembled under clean
conditions, preferably in a shop
environment. Carefully read and
understand this manual before attempting
to adjust set pressure or repair the pilot.
For information not contained in this
manual, please contact:
Groth Corporation
13650 N. Promenade Blvd,
Stafford, TX, 77477
281-295-6800 (Phone)
281-295-6999 (Fax)
This manual is intended to provide
recommended procedures and practices
for installation, operation, and
maintenance of the Groth model 1402
pilot. Any standard procedures and
practices developed for a specific plant or
process should supersede this manual.
While this manual cannot cover all
possible contingencies, following these
guidelines should provide safe, reliable
valve performance.
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 and may require
additional over-pressure to provide rated
flow capacity. Consult factory for any
questions related to this over-pressure
condition.
POV relief pressure is 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 larger. 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.