
6
ANDERSON GREENWOOD SERIES 500 PILOT OPERATED SAFETY RELIEF VALVES
INSTALLATION AND MAINTENANCE INSTRUCTIONS
3 PILOT MAINTENANCE
3.1 Disassembly
To facilitate assembly, place all parts
removed in an orderly arrangement so that
the correct parts can be assembled in the
proper sequence. Refer to Figure 3 for parts
description and location.
NOTE
If pilot is equipped with a lift lever, the lift leverhandle
assembly must be unscrewed from cap before continuing
with disassembly. Hold lift lever in position shown
in Figure 8, unscrew bushing (Item 14) from cap and
remove handle assembly (Items 13, 14, 15, 32 and 45).
Unscrew and remove cap. Loosen jam nuts
and release spring compression by backing out
adjusting screw. Remove bonnet, spring and
spring washer. Remove lift lever adapter, rod
and support spring where used.
Loosen spindle nut before loosening jam nuts.
The spindle jam nuts serve as wrench flats on
the spindle. Remove remainder of accessible
parts except spindle. Remove nozzle
witha⅜ in.
square
drive socket extension. Remove the
spindle assembly by pushing it up through
the body.
3.2 Assembly
Assemble pilot in reverse order of disassembly.
Take care not to scratch the sealing face of
the seat or nozzle. If scratched or nicked, it
must be replaced or lapped to prevent leaking.
Lubricate all screw threads and bearing end
of spring washers with NG-165 Never-Seez
lubricant. Use Dow Corning No. 33 Silicone
grease on all surfaces of the spring washer
bearing if installed. Lubricate the sealing flange
of the nozzle to prevent galling. Do not lubricate
spindle, lower end of spindle seat, nozzle face,
or PTFE seals.
3.4 Bolt make-up (item 38)
Tighten the six ⅜ in. case bolts alternately
opposite each other to approximately 32 to
36ft·lb (23.6 to 26.55 Nm).
3.3 Pilot diaphragm assembly
3.3.1 Boost diaphragm (lower diaphragm)
Install upper diaphragm shield on top
of lower diaphragm shield. Install boost
diaphragm (Item 55) over spindle on
top of the lower and upper diaphragm
shield, with spindle gaskets (Item 56) and
diaphragm gaskets (Item54 or 57) on
both sides of the diaphragm. For pressure
below 120 psi (8.27 bar), use a PTFE
diaphragm with FEP diaphragm gaskets.
For pressure between 121 to 180psi
(8.34 to 12.41 bar), use a Hastelloy
®
diaphragm with FEP diaphragm gaskets.
For pressure above 180 psi (12.41 bar),
use a Hastelloy
®
diaphragm with Peek
diaphragm gaskets. Install boost plate
(item 8) on top of the boost diaphragm.
3.3.2 Sensing diaphragm (upper diaphragm)
Install sense diaphragm (Item 55) on
top of spacer ring, with a diaphragm
gasket and a spindle gasket below the
diaphragm. For set pressure up to 30psi
(2.07 bar), use a PTFE diaphragm with
a FEP diaphragm gasket. For pressure
between 30 to 180 psi (2.07
to 12.41 bar)
,
use a Hastelloy®diaphragm with a FEP
diaphragm gasket. For pressure above
180 psi
(12.41 bar)
, use a Hastelloy®
diaphragm with a PEEK diaphragm
gasket.
Hastelloy®is a registered trademark of
HaynesInternational.