ES-774

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Job Location –––––––––––––––––––––––––––––––––––––––––– Approval ––––––––––––––––––––––––––––––––––––––––––––––

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LEAD FREE*
Series 774
Double Check Valve Assemblies
Sizes: 2½" – 12"
Series 774 Double Check Valve Assemblies are de­signed to pre­vent
the reverse flow of polluted water from en­ter­ing into the potable 774 OSY
water system. This se­ries can be ap­plied, where approved by the
lo­cal authority having ju­ris­dic­tion, on non-health hazard installations.
Fea­tures short end-to-end dimensions, light weight stain­less steel
body, and the lowest head loss available.

Features
• Torsion spring check valve provides low head loss
• Short lay length is ideally suited for retrofit installations
• Stainless steel body is half the weight of competitive designs
reducing installation and shipping cost
• Stainless steel construction provides long term corrosion
protection and maximum strength
• Single top access cover with two-bolt grooved style coupling
for ease of maintenance
• Thermoplastic and stainless steel check valves for
trouble-free operation
• No special tools required for servicing
• Compact construction allows for smaller vaults and enclosures
• May be installed in horizontal or vertical "flow up" position

Specifications
A Double Check Valve Assembly shall be in­stalled at each not­ed
location to prevent the un­want­ed reversal of pol­lut­ed water into the
potable water supply. The main valve body shall be manufactured
Now Available
from 300 series stainless steel to pro­vide corrosion resistance. The WattsBox Insulated Enclosures.
check valves shall be of ther­mo­plas­tic construction with stainless For more information, send for literature ES-WB.
steel hinge pins, cam arm, and cam bearing. The check valves shall
uti­lize a sin­gle torsion spring design to minimize pressure drop
through the as­sem­bly. The check valves shall be modular and shall NOTICE
seal to the main valve body by the use of an O-ring. There shall be The information contained herein is not intended to replace the full
no brass or bronze parts used within the check valve assembly. product installation and safety information available or the experience
The valve cover shall be held in place through the use of a single of a trained product installer. You are required to thoroughly read
grooved style two-bolt coupling. The main assembly shall consist all installation instructions and product safety information before
of two in­de­pen­dent­ly op­er­at­ing torsion spring check as­sem­blies, beginning the installation of this product.
two resilient seat­ed iso­la­tion valves, and four ball valve type test
cocks. The as­sem­bly shall be a Watts Series 774. NOTICE
Inquire with governing authorities for local installation requirements
*The wetted surface of this product contacted by consumable
water contains less than 0.25% of lead by weight.

Watts product specifications in U.S. customary units and metric are approximate and are provided for reference only. For precise measurements,
please contact Watts Technical Service. Watts reserves the right to change or modify product design, construction, specifications, or materials with-
out prior notice and without incurring any obligation to make such changes and modifications on Watts products previously or subsequently sold.
Available Models Testcocks
Suffix:
NRS Non-rising stem resilient seat­ed gate valves
Stainless Grooved
OSY UL/FM resilient seated outside stem & yoke gate Steel Cover Coupling
valves
Resilient
LF Without shutoff valves Captured Disc
S Cast iron strainer Torsion
Spring
**OSY FxG Flanged inlet gate connection and grooved outlet
gate connection
Replaceable
**OSY GxF Grooved inlet gate connection and flanged outlet Seat
gate connection
**OSY GxG Grooved inlet gate connection and grooved outlet
gate connection Laser Cut /
Polished Cam
Available with grooved NRS gate valves - consult factory** Arm
Post indicator plate and operating nut available - consult factory**
**Consult factory for dimensions

Materials Standards
All internal metal parts: 300 Series stainless steel AWWA C510-92, CSA B64.5
Main valve body: 300 Series stainless steel
Check assembly: Noryl® Approvals
Flange dimension in accordance with AWWA Class D

Pressure - Temperature
1015 (4" - 10" (OSY only)
Temperature Range: 33ºF – 110ºF (0.5ºC – 43ºC) continuous OSY only)
Maximum Working Pressure: 175psi (12.1 bar)
For 12" assembly approvals consult factory.

Dimensions - Weight
t

C (Open)
t

G
t
t
t
t
D
t
N
L
t
t

t
S
A
tt

M
t

SIZE DIMENSIONS WEIGHT

A C (open) D G L M N S w/Gates w/o Gates
OSY NRS Screen Removal
in. in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm lbs. kgs. lbs. kgs.
21/2 37 940 163/8 416 93/8 238 31/2 89 10 254 22 559 10 254 61/2 165 7 178 140 64 53 24
3 38 965 187/8 479 101/4 260 33/4 95 15 381 22 559 101/8 257 7 178 71/2 191 215 98 55 25
4 40 1016 223/4 578 123/16 310 41/2 114 10 254 22 559 121/8 308 81/4 210 9 229 225 102 58 26
6 481/2 1232 301/8 765 16 406 51/2 140 15 381 271/2 699 181/2 470 131/2 343 11 279 375 170 105 48
8 521/2 1334 373/4 959 1915/16 506 63/4 171 15 381 291/2 749 215/8 549 151/2 394 131/2 343 561 254 169 77
10 551/2 1410 453/4 1162 2313/16 605 8 200 15 381 291/2 749 26 660 181/2 470 16 406 763 346 179 81
12 571/2 1461 531/8 1349 263/4 679 91/2 241 15 381 291/2 749 297/8 759 213/4 552 19 483 1033 469 209 95
Noryl® is a registered trademark of General Electric Company
Capacity
Rated working pressure 175psi (12.1 bar) * Rated flow, ** UL Tested

kPa psi
21⁄2" kPa psi 8"
83 12 * ** 103 15 * **
69 10 83 12
55 8
62 9
41 6
28 4 41 6

14 2 21 3

0 25 50 100 150 200 250 300 350 400 450 500 525 gpm
95 190 380 570 760 950 1140 1330 1520 1710 1900 1995 lpm 0 250 500 750 1000 1250 1500 1750 2000 2250 2500 gpm
15 fps 950 1900 2850 3800 4750 5700 6650 7600 8550 9500 lpm
4.6 mps 15 fps
4.6 mps
kPa psi 3" 10"
83 12 * ** kPa
103
psi
15 * **
69 10
83 12
55 8
62 9
41 6
41 6
28 4
21 3
14 2
0250 500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000 3250 3500 gpm
0 25 50 100 150 200 250 300 350 400 450 500 550 600 gpm 950 1900 2850 3800 4750 5700 6650 7600 8550 9500 10450 11400 12350 13300 lpm
95 190 380 570 760 950 1140 1330 1520 1710 1900 20902280 lpm fps
15 fps mps
4.6 mps

4"
kPa psi 12"
103 15 * ** kPa psi
110 16 * **
83 12
97 14
62 9
83 12
41 6 69 10
21 3 55 8
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 gpm 41 6
171 380 570 760 950 1140 1330 1520 1170 1900 2090 2280 2470 2660 2850 lpm 28 4
5 10 15 fps 14
1.5 3 4.6 mps
2
6" 0 500 1000 1500 2000 2500 3000 3500 4000 4500 gpm
kPa psi 1900 3800 5700 7600 9500 11400 13000 15200 17100 lpm
103 15 * ** 5 10 fps
1.5 3 mps
83 12
62 9
41 6
21 3

0100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 gpm
380 760 1140 1520 1900 2280 2660 3040 3420 3800 4180 4560 4940 5320 5700 lpm
5 7.5 10 15 fps
1.5 2.3 3 4.6 mps

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Canada: T: (888) 208-8927 • F: (888) 479-2887 • Watts.ca
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