Groth 1400 - Manual (Page 6)

5
remote sense connection is specified, an
external sense line must be installed. See
the appropriate manual or attached tag for
recommendations. If the valve utilizes a
1402 Pilot Valve, there will be two
connections to the tank. The connections
can only be combined (with a tee) at the
tank connection.
MAINTENANCE
Safety Warning
If the valve must be removed from the tank for
any reason, make sure that all pressure has
been released before the flange fasteners are
loosened. Refer to your company procedures
before venting the tank pressure and when
handling toxic or otherwise hazardous materials.
Observe all standard safety precautions as
specified on Material Safety Data Sheets for the
product(s) in the system while removing the
valve and when repairing it.
The 1460 POV does not require routine
lubrication or adjustments. It should be checked
periodically, at least twice a year, to confirm that
the valve is functioning properly and that the set
point is correct. Test connections can be
provided to facilitate testing the valve in the field.
The pilot valve is designed to function in a fail-
safe manner. The failure of a seal or diaphragm
will cause pressure to be vented to the
atmosphere; the resulting loss in pressure will
cause the main valve to open under rising
pressure.
Periodic inspection for seat tightness should be
done to ensure compliance with local air
pollution control requirements. If the valve
relieves to the atmosphere, this may
accomplished with a gas detector calibrated for
the principle product in the system.
The valve will need to be periodically removed
from the tank for inspection of diaphragms,
gaskets and seals. When this is done, the valve
must be handled carefully using the lifting eyes
on the actuator housing.
Refer to handling instructions listed in the
Installation section of this manual.
If a vapor leak is detected, it will likely be from
one of the following sources:
1. Pilot valve
2. Main valve actuator
3. Main valve diaphragm
4. Body - nozzle flange joint gasket
Refer to the troubleshooting section of this
manual or the pilot valve manual for probable
causes for these type of problems.
The main and pilot valve actuator housings,
valve bodies, pallet assemblies and other
components are exposed to the process vapor.
DISASSEMBLY
The 1400 series valves can be simplified into
three modules. These modules can be seen in
the figures below:
Weatherhood (with Pilot)
Outlet (with Pilot)
Vacuum (integral with body)
Before any disassembly or assembly, make sure
that there is NO PRESSURE (positive or
negative) in the system.
Outlet/ Weatherhood Disassembly
1. Disconnect the tubing connections (pilot to
main valve).
2. Remove the pilot valve. Refer to appropriate
pilot valve manual for disassembly
instructions.
3. Remove all fasteners holding the actuator
housings together.
4. Carefully lift the upper housing to avoid
damaging the actuator diaphragm.
5. Remove the housing gaskets.
6. Remove the actuator diaphragm and the
screw holding the support plate.
7. Remove the actuator support plate.
8. Remove the fasteners holding the lower
housing to the body (Models 1420 & 1460),
or weatherhood posts (Models 1400 &
1430).
9. Lift lower housing and stem guide assembly.
This assembly will slide over the stem.
10. Lift the stem and pallet assembly out of the
valve, invert it, and hold the stem in a soft
chuck vise (to avoid damage to the stem).
11. Remove the nut, to disassemble the pallet
assembly.