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Anderson Greenwood SerieS 400 PiSton Pilot PoPrV
InstallatIon and MaIntenance InstructIons
1.4 Maintenance
Anderson Greenwood recommended main valve
and pilot maintenance procedures including
pilot set pressure adjustment and valve
assembly testing are described in the following
paragraphs. Following these procedures in
a regular pressure relief valve maintenance
program appropriate for the specific operating
conditions will ensure satisfactory valve
performance and provide optimum service life.
Should the pressure/media requirements of a
pilot operated pressure relief valve be outside
the capabilities of the repair facility, contact
Anderson Greenwood for specific instructions
before starting any maintenance activity.
this manual is provided as a general guide for
the maintenance of the safety valves described
herein. it does not include procedures
covering all valve configurations and variations
manufactured by Anderson Greenwood. the
user is advised to contact Anderson Greenwood
or one of our authorized representatives for
assistance with valve configurations and
variations not covered in this manual.
2 MAin vAlve MAintenAnCe
2.1 disassembly
Before beginning disassembly, bleed off any
pressure trapped in the main valve or pilot.
refer to Figure 1A (piston/seat type XX3) and
Figure 1B (piston/seat type XX9) for parts
description and location.
remove cap (item 17) from the body (item 1).
remove the liner seal (item 6), liner (item 5)
and piston (item 10). remove the soft goods
from the piston. if the piston is equipped with
a wedge ring (item 23), clean and retain for
use during assembly. the dipper tube (item 4)
is swaged in place and no attempt should be
made to remove it. the nozzle (item 3) should
not be removed unless it is damaged or the
nozzle seal (item 2) is leaking.
valve size and type
X = Main valve piston/seat type, 3 or 9
1/1.5 x 2 type 44X/45X (D, e and F orifice)
1.5 x 2/3 type 44X/45X (G and H orifice)
2" type 44X/45X
3" type 44X/45X
4" type 44X/45X
6" type 44X/45X
8" type 44X/45X
1.5" type 46X
2" type 46X
3" type 46X
4" type 46X
6" type 46X
8 x 88 type 46X
8 x 10 type 46X
10" type 46X
note
Do not remove lock pin and lift adjusting bolt (items 11
and 12) on valves so equipped unless nozzle is
removed. this bolt controls the piston lift and hence
the valve's relieving capacity. if either or both the
nozzle and lift bolt were removed, then lift must be
reset following the procedure of paragraph 2.3.3
(type XX3 or paragraph 2.3.4 (type XX9).
2.1.1 Nozzle and nozzle seal disassembly
refer to Figure 2 for parts description and
location.
1. remove lock pin and lift adjusting bolt from
piston, if applicable.
2. Place liner in body and piston, without seat
or seat retainer, into liner and on top of
nozzle.
3. Place appropriate spacer (see table i) on top
of piston and then the cap over the spacer.
4. thread the appropriate number of cap bolts
(see table i) into threaded holes on top of
body. if two bolts are used, they should be
180° apart. When using four bolts, they
should be 90° apart. Always use the shortest
cap bolts supplied with the valve unless
all cap bolts are required. For example,
the 1" type 40/50 is equipped with two 1.50"
long bolts and two 1.88" long bolts but only
the two 1.50" long bolts should be used.
However, the 2" type 40/50 is equipped with
two 1.25" long bolts and two 1.62" long bolts
and all four bolts are required for nozzle
installation.
5. tighten cap bolts evenly to the torque listed
in table i to compress nozzle seal.
6. Use a punch or bar with a light hammer
and tap on the nozzle retainer teeth to
loosen the nozzle retainer. Unthread nozzle
retainer approximately ½ turn.
7. loosen cap bolts to remove load from nozzle.
remove components from main valve.
Min. nozzle projection
height (in)
.045
.040
.035
.035
.035
.035
.035
.035
.035
.035
.030
.030
.030
.030
.030
2.2 Main valve nozzle rework
Should the main valve nozzle seating face
become nicked or scratched such that the main
valve seat does not seal, the imperfections
can be removed by polishing the seating face
with 400 grit sandpaper. if necessary, the
nozzle may be removed from the body and
the nozzle seating face (only the seating face)
may be remachined and/or polished using
400 grit sandpaper on a flat surface plate. the
resurfaced nozzle must be within the limiting
dimensions shown in the table and figure
below. if the resurfaced seating face standoff is
less than the minimum projection height listed,
the nozzle must be replaced.
32
Minimum
projection
32
.010
r.020
2
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