Submittal Sheet

Page 2 of 2
a company
®
®
WILKINS a Zurn company, 1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
IN CANADA: ZURN INDUSTRIES LIMITED, 3544 Nashua Dr., Mississauga, Ontario L4V 1L2 Phone:[phone] Fax:[phone]
Product Support Help Line: 877-BACKFLOW (877-222-5356) • Website: http://www.zurn.com
MODEL 475 & 475V 8" & 10" (STANDARD & METRIC)
0
5
10
15
20
0 1000 2000 3000 4000
FLOW RATES (GPM)
PRESSURE LOSS (PSIG)
0
34
69
103
138
0.0 63.1 126.2 189.3 252.4
FLOW RATES (l/s)
PRESSURE LOSS (kpa)
TYPICAL INSTALLATION
Local codes shall govern in-
stallation requirements. To
be installed in accordance
with the manufacturers’
instructions and the lat-
est edition of the Uniform
Plumbing Code. Unless
otherwise specified, the
assembly shall be mounted
above adequate drains with
sufcient side clearance for
testing and maintenance.
The installation shall be
made so that no part of the
unit can be submerged.
SPECIFICATIONS
The Reduced Pressure Principle Backow Preventer shall be ASSE® Listed 1013, and supplied with full port gate valves.
The main body and access covers shall be epoxy coated ductile iron (ASTM A 536 Grade 4), the seat ring and check
valve shall be NORYL™, the stem shall be stainless steel (ASTM A 276) and the seat disc elastomers shall be EPDM.
Center stem guided design shall incorporate two torsion springs to bias the check in the closed position. The rst and
second checks shall be accessible for maintenance without removing the relief valve or the entire device from the line.
If installed indoors, the installation shall be supplied with an air gap adapter. The Reduced Pressure Principle Backow
Preventer shall be a WILKINS Model 475 or 475V.
OUTDOOR INSTALLATION VERTICAL INSTALLATION
FLOW CHARACTERISTICS
OUTDOOR INSTALLATION
475 (with BGVIC valves)
Capacity thru Schedule 40 Pipe (GPM)
Pipe size 5 ft/sec 7.5 ft/sec 10 ft/sec 15 ft/sec
2 1/2" 75 112 149 224
3" 115 173 230 346
4" 198 298 397 595
6" 450 675 900 1351
8" 780 1169 1559 2339
10" 1229 1843 2458 3687
12" 1763 2644 3525 5288
MODEL
SIZE
DIMENSIONS (approx.)
A1 SETTER
END TO
END FLS
A1 SETTER
END TO
END MJS
in. mm in. mm in. mm
4 100 31 5/16 795 29.313 745
6 150 34 3/4 884 32.75 832
8 200 47 1194 44.625 1133
10 250 51 1295 47 1194

Rated Flow (Established by approval agencies)
MODEL 475 & 475V 4" & 6" (STANDARD & METRIC)
0
5
10
15
20
0 400 800 1200 1600
FLOW RATES (GPM)
PRESSURE LOSS (PSIG)
0
34
69
103
138
0.0 25.2 50.5 75.7 100.9
FLOW RATES (l/s)
PRESSURE LOSS (kpa)
DIRECTION OF FLOW
6" MIN.
WILKINS VALVE
SETTER
PROTECTIVE
ENCLOSURE
A1
AIR GAP
6" MIN.
WILKINS VALVE
SETTER
PROTECTIVE
ENCLOSURE
A1
AIR GAP
DIRECTION OF FLOW
DIRECTION OF FLOW
DRAIN
AIR
GAP
12" MIN.
8" (200mm)
10" (250mm)
6" (150mm)
4" (100mm)