Plunger Assembly, Differential Valve Spring, and Differen-
tial Valve Housing Cover. Make sure the Differential Valve
Spring is in its proper position over the Differential Valve
Plunger Locknut and in the Differential Valve Housing
Cover recess. Tighten the Differential Valve Housing
Cover Cover Bolts using a cross-draw sequence.
Leakage From Automatic Drain Valve (Fig. 7) and
Water Seat Disc (22 - Fig. 2) Replacement
When replacing the Water Seat Disc to stop leakage from
the Automatic Drain Valve, the Disc Retaining Ring (23 -
Fig. 2) is also to be replaced. Prior to inserting the Water
Seat Disc into the Seat Ring groove that accepts the
Water Seat Disc, the groove must be completely cleaned
and lubricated with Dow Corning FS3452 Flurosilicone
Grease (41 - Fig. 2).
Use only Dow Corning FS3452
Flurosilicone Grease for lubricating the groove. The Disc
Retaining Ring must be cut so that there is a 1/16 inch
gap between the two ends of the Disc Retaining Ring af-
ter the Disc Retaining Ring is installed, and the the two
ends of the Disc Retaining Ring must be visible in the
Seat Ring notch that is positioned towards the rear of the
Seat Ring.
Leakage From Automatic Drain Valve (Fig. 7) and
Clapper (9 - Fig. 2) / Air Seat Disc (24 - Fig. 2)
Replacement
When replacing either the Clapper or Air Seat Disc to
stop leakage from the Automatic Drain Valve, care is to
be taken when tightening the Cap Screw (11 - Fig. 2). Un-
der tightening may result in air leakage from the Automat-
ic Drain Valve (Fig. 7). Over tightening may crack the Clap-
per resulting in water leakage from the Automatic Drain
Valve (Fig. 7).
Differential Valve Plunger (31 - Fig. 2) and/or Differen-
tial Valve Plunger Nose (32 - Fig. 2) Replacement
When removing the Differential Housing Cover to gain ac-
cess to the Differential Valve Plunger Assembly, first
loosen all of the Differential Housing Bolts, and then re-
place the top two Differential Housing Bolts with 6 inch
long stud bolts as shown in Figure 11. The lower two Dif-
ferential Housing Bolts and Cover can then be removed
while the Differential Housing remains temporarily sup-
ported by the stud bolts.
When either the Differential Valve Plunger or Differential
Valve Plunger Nose requires replacement, both parts are
to be replaced at the same time, adjustment of the Differ-
ential Valve Plunger Assembly will be required, and a Roll
Pin (29 - Fig. 2) must be utilized to complete the installa-
tion.
Adjustment of the Differential Valve Plunger Assembly is
accomplished by varying the thread engagement be-
tween the Plunger Nose and the Plunger. Start with an
overall assembly length of 4-7/8 inches, and then insert
the Differential Valve Assembly into the Differential Valve
Seat. With the Clapper Assembly seated and while pulling
the Retaining Lever from left to right, push the Differential
Valve Plunger Assembly completely into the Differential
Valve Seat. Under these conditions there is to be a 1/16
inch gap between the Plunger Nose and the Retaining
Lever. When the Retaining Lever is released, the spring
of the Water Seat and Air Seat Discs should push the Re-
taining Lever back into contact with the Plunger Nose. Ad-
just the engagement of the Plunger Nose accordingly.
After assuring proper engagement of the Plunger Nose
with the Plunger, remove the Plunger Assembly from the
Valve and drill a 5/32 inch diameter hole through the
threaded shank of the Plunger Nose using the 5/32 inch
diameter holes through the Plunger as a guide, and then
insert the Roll Pin (29 - Fig. 2) to complete the assembly.
Before reassembly, verify that the O-Ring (34 - Fig. 2) is
lubricated with Grease (41 - Fig. 2). Use only Dow Corn-
ing FS3452 Flurosilicone Grease for lubricating the Differ-
ential Valve Plunger O-ring.
ORDERING PROCEDURE
Please Specify:
1. 3 Inch (DN80) Model A Preaction Valve (#3000)
2. 3 Inch Electric/Pneumatic Double Interlock Trim
(#3008)
Separately Ordered Items:
1. Solenoid Valve For Releasing Service (Ref. 2-5.1.31)
2. Air Maintenance Device:
Model S460 Pressure Reducing Type (#1612), or
Model S465 Compressor Control Type (#1613)
Optional:
1. Double Interlock Accelerator Trim complete with
Model S430 Accelerator (#3644)
2. Priming and Priming Test Trim
For Use With Model A Preaction Valve (#3022)
Refer to Price List for for complete listing of Part
Numbers with respect to trim, replacement parts, etc.
AVAILABILITY AND SERVICE
Star Sprinkler Inc. products and devices are available
worldwide through a network of independent distributors.
Please contact Star Sprinkler Inc. for information and the
name and address of the Star distributor in your area.
LIMITED WARRANTY
Seller warrants for a period of one year from date of ship-
ment (warranty period) that the products furnished here-
under will be free of defects in material and workmanship.
For further details on Warranty, contact Star Sprinkler Inc.
STAR SPRINKLER INC.
Page 12
2-4.1.10
7071 S. 13th Street • Suite 103
Oak Creek, WI 53154
414-570-5000 • 800-558-5236
PRINTED IN U.S.A. 6-00
FIGURE 11
DIFFERENTIAL HOUSING COVER REMOVAL
5/8-11 UNC x 6"
STUD
BOLTS
HOUSING IS
SUPPORTED
BY STUD
BOLTS
OBSOLETE
