Watts 774DCDA User Manual

For Non-Health Hazard Applications

ES-774DCDA

Job Name

Job Location

Engineer

Approval

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Series 774DCDA

Double Check Detector Assemblies

Sizes 21⁄2" – 12" (65 – 300mm)

Series 774DCDA Double Check Detector Assemblies are designed for use in
accordance with water utility non-health hazard containment requirements. It
is mandatory to prevent the reverse flow of fire protection system substances,
i.e., glycerin wetting agents, stagnant water and water of non-potable quality
from being pumped or siphoned into the potable water supply.

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

• Furnished with

• Detects underground leaks and unauthorized water use

• May be installed horizontal or vertical “flow up” position

Specifications

A Double Check Detector Assembly shall be installed on fire protection sys­tems when connected to a potable water supply. Degree of hazard present is
determined by the local authority having jurisdiction. The assembly shall
consist of two positive seating check valves located between two resilient
seated shutoffs with a hydraulically balanced bypass line and four test
cocks. The main valve body shall be manufactured from 300 Series stainless
steel to provide corrosion resistance. The check valves shall be of thermo­plastic construction with stainless 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 seal to the main valve body by the use of an O-ring. There shall be no
brass or bronze parts used within the check valve assembly. The check valve
seats shall be of molded thermoplastic construction. The use of seat screws
as a retention method is prohibited. All internal parts shall be accessible
through a single cover on the valve assembly. The valve cover shall be held
in place through the use of a single grooved style two-bolt coupling. The
bypass line shall be hydraulically sized to accurately measure low flow. The
bypass line shall consist of a meter, a small diameter double check assem­bly with test cocks and isolation valves. The bypass line double check valve
shall have two independently operating modular poppet check valves, and
top mounted test cocks. The assembly shall be a Watts Series 774DCDA.

5

⁄8" x 3⁄4" (16x19mm) bronze meter (gpm or cfm)

Contractor

Approval

Contractor’s P.O. No.

Representative

Test Cock

Bypass Meter

over

C

est Cock

T

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774DCDAOSY

Grooved Coupling

Replaceable

Seat

Laser Cut Polished Cam Arm

Bypass Double

heck Valve

C

est Cock

T

Resilient

Disc

Available Models

Suffix:

LF – without shutoff valves
OSY – UL/FM outside stem and yoke resilient seated gate valves
*OSY FxG – flanged inlet gate connection and grooved outlet gate con-

*OSY GxF – grooved inlet gate connection and flanged outlet gate

*OSY GxG – grooved inlet gate connection and grooved outlet gate

CFM – cubic feet per minute meter
GPM – gallons per minute meter
Available with grooved NRS gate valves - consult factory*

Post indicator plate and operating nut available - consult factory*
*Consult factory for dimensions

nection

connection

connection

Now Available

WattsBox Insulated Enclosures.

For more information, send for literature ES-WB.

IMPORTANT: INQUIRE WITH GOVERNING AUTHORITIES

FOR LOCAL INSTALLATION REQUIREMENTS

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 with­out prior notice and without incurring any obligation to make such changes and modifications on Watts products previously or subsequently sold.

Materials

All internal metal parts: 300 Series stainless steel, Main valve body: 300

eries stainless steel, Check assembly: Noryl

S
dance with AWWA Class D.

®

lange dimensions in accor-

F

Pressure - Temperature

Temperature Range: 33°F – 110°F (0.5°C – 43°C) continuous

Standards

AWWA C510, CSA B64.5

Approvals

(21⁄2" - 10" only)
(65 - 250mm)

Pressure Range: 175psi (12.1 bar)

Capacity

Flow curves as tested by Underwriters Laboratory per UL 1469, 1996 * Rated flow **UL Tested

Pa psi

k

83 12

69 10

55 8

41 6

28 4

14 2

Pressure Drop

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

kPa psi

83 12

9 10

6

55 8

41 6

28 4

14 2

Pressure Drop

25 50 100 150 200 250 300 350 400 450 500 550 600 gpm

0

95 190 380 570 760 950 1140 1330 1520 1710 1900 2090 2280 lpm

kPa psi

103 15

83 12

62 9

41 6

Pressure Drop

21 3

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 gpm

171 380 570 760 950 1140 1330 1520 1170 1900 2090 2280 270 2660 2850 lpm

5 10 15 fps

1.5 3 4.6 mps

G

P

Noryl®is a registered trademark of
SABIC Innovative Plastics™.

21⁄2" (65mm)

*

5 fps

1

4.6 mps

**

kPa psi

103 15

83 12

62 9

41 6

Pressure Drop

1 3

2

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 gpm

Flow

3" (80mm)

Flow

4" (100mm)

Flow

*

15 fps

4.6 mps

**

*

**

C

(Open)

D

kPa psi

83 12

62 9

41 6

21 3

Pressure Drop

0 250 500 750 1000 1250 1500 1750 2000 2250 2500 gpm

kPa psi

103 15

83 12

62 9

41 6

Pressure Drop

21 3

0 250 500 750 1000 1250 1500 1750 2000 2250 2500 3000 3500 gpm

kPa psi

110 16

97 14

83 12

69 10

55 8

41 6

28 4

Pressure Drop

14 2

0 500 1000 1500 2000 2500 3000 3500 4000 4500 gpm

L
A

SIZE (DN) DIMENSIONS WEIGHT

in. mm in. mm in. mm in. mm in. mm in. mm in. mm lbs. kgs. lbs. kgs.

21⁄2 65 38 965 163⁄8 416 31⁄2 89 10 250 22 559 121⁄2 318 155 70 68 31

3 80 38 965 18
4 100 40 1016 22
6 150 48

8 200 52
10 250 55
12 300 57

A C (OSY) DG L Pw/Gates w/o Gates

7

⁄8 479 33⁄4 95 10 250 22 559 13 330 230 104 70 32

3

1

⁄2 1232 301⁄8 765 51⁄2 140 15 381 271⁄2 699 151⁄2 394 390 177 120 54

1

⁄2 1334 373⁄4 959 63⁄4 171 15 381 291⁄2 749 181⁄4 464 572 259 180 82

1

⁄2 1410 453⁄4 1162 8 200 15 381 291⁄2 749 191⁄2 495 774 351 190 86

1

⁄2 1461 531⁄8 1349 91⁄2 241 15 381 291⁄2 749 21 533 1044 474 220 100

⁄4 578 41⁄2 114 10 250 22 559 141⁄2 368 240 109 73 33

048

1

(OSY only)

6" (150mm)

*

380 760 1140 1520 1900 2280 2660 3040 3420 3800 4180 4560 4940 5320 5700 lpm

5 10 15 fps

.5 3 4.6 mps

1

Flow

**

8" (200mm)

*

950 1900 2850 3800 4750 5700 6650 7600 8550 9500 lpm

5 10 15 fps

1.5 3 4.6 mps

Flow

**

10" (250mm)

* **

950 1900 2850 3800 4750 5700 6650 7600 8550 9500 11400 13300 lpm

1900 3800 5700 7600 9500 11400 13300 15200 17100 lpm

5 10 15 fps

1.5 3 4.6 mps

Flow

12" (300mm)

5 10 fps

1.5 3 mps

Flow

A Watts Water Technologie s Compa ny

USA: No. Andover, MA • Tel: [phone] • Fax: [phone] • www.watts.com

Canada: Burlington, ON • Tel: [phone] • Fax: [phone] • www.wattscanada.ca

ES-774DCDA 1128 © 2011 Watts