Grain Systems PNEG-526 - Manual (Page 175)

Servicing – General Instructions
1. Make sure the regulator is entirely depressured before servicing.
2. Carefully note location and position of all disassembled parts to be
certain reassembly is correct. Inspect each one carefully and re-
place those that are worn or damaged or otherwise unsatisfactory.
3. A moderate application of lubricant to O-ring 13 will help assure free
stem movement and a tight seal. Similar application of lubricant to
the other O-rings or Tetraseals will help assure their
tightness.
Do not use petroleum base lubricants.
4. Bolted connections should be tightened evenly and firmly.
Carefully tighten diaphragms into place. Bolts must be tight enough
to prevent leakage, but not so tight that the diaphragm material is
crushed or damaged.
5. Upon completion of servicing, make certain that regulator installa-
tion is entirely free of leaks.
To Service Valve (15)
1. Remove bolts 38 and remove bottom cap 37 and Tetraseal 32.
2. Remove retaining ring 16a. Use Truarc 0200 pliers, Invensys Part
No. 1190646.
3. Remove both halves of valve holder 16b.
4. Remove valve 15 (wave washer 14 will probably also come off...do
not lose it).
– To reassemble, replace parts in reverse sequence.
To Service Main Diaphragm (11d)
1. Remove top cap 1, and release and remove adjustment 3. On high
pressure Model remove cap 1a, release adjustment 3a, and remove
cover 5 and button 7a. Mark or measure position of adjustment 3 or
3a. Use this to return adjustment to this setting during reassembly.
2. Remove spring 9.
3. Remove bolts 22 and upper case 21.
4. Rotate diaphragm assembly 11 counterclockwise (this unscrews 11h
from 12d) and remove.
5. To disassemble diaphragm assembly, remove nut 11a. Carefully
note location and position of all parts to be certain of correct reas-
sembly. Abrasive side of emery cloth washers face against
diaphragm.
– To reassemble, replace parts in reverse sequence.
Make the screwed connection between 11h and 12d loose by
approximately 1 /
2
turn. To do this, carefully rotate diaphragm
assembly 11 clockwise until this screwed connection bottoms (do
not jam it together). Then, back-off diaphragm assembly 11 counter-
clockwise approximately 1 /
2
turn...this is very important...the 11h to
12d screwed connection must not be tight.
To Service Orifice (19)
1. Remove valve 15 per section “To Service Valve (15)”.
2. Remove main diaphragm assembly 11 per steps 1 through 4 “To
Service Main Diaphragm (11d)”.
3. Remove seal diaphragm assembly 12 per steps 3 and 4 under “To
Service Seal Diaphragm (12b)”.
4. Remove retaining ring 19a. Use Truarc 0600 pliers, Invensys Part
No. 1190648.
5. Remove orifice 19 through top opening.
– To reassemble, replace parts in reverse sequence.
(On reassembly, be sure that 19a is fully seated in its groove. Also,
beveled edge of 19a faces downward toward bottom cap 37.)
To Service Seal Diaphragm (12b)
1. Remove valve 15 per section “To Service Valve (15)”.
2. Remove main diaphragm assembly 11 per steps 1 through 4 “To
Service Main Diaphragm (11d)”.
3. Remove bolts 25 and lower diaphragm case 24.
4. Remove bolts 29 and centerpiece 27, and then remove seal
diaphragm assembly 12.
5. To disassemble 12, unscrew piston 12a from stem 12d. Use a
spanner wrench in notch in skirt of piston (this can also be done by
inserting a standard 7 /
32
" Allen wrench in the notch).
– To reassemble, replace parts in reverse sequence.
Make certain that fabric side of seal diaphragm 12b faces upward
and “rubber” side faces downward toward body.
Do not pinch loop in seal diaphragm 12b between ring 33 and
centerpiece 27. Also, rounded edge of 33 faces upward toward
seal diaphragm 12b.
Periodic Inspection: Regulators are pressure control devices with
numerous moving parts subject to wear that is dependent upon
particular operation conditions. To assure continuous satisfactory
operation, a periodic inspection schedule must be adhered to with
the frequency of inspections, determined by the severity of service
and applicable laws and regulations.
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