Install Instructions

ManualsBrandsWatts ManualsBackflow Preventers4" 757 Double Check Valve Assembly (OSY)

Series 757a, 757aDCDA

757Na, 757NaDCDA

Double Check Valve Assemblies

Double Check Detector Assemblies

Sizes: 2

⁄2" – 6" (65 – 150mm)

• Installation

• Service

• Repair Kits

• Maintenance

For field testing procedure, send for IS-TK-DL, IS-TK-9A,

IS-TK-99E and IS-TK-99D.

For other repair kits and service parts, send for PL-RP-BPD

and F-RK-DC.

For technical assistance, contact your local Watts representative.

Watts 757a OSY

IMPORTANT: Inquire with governing authorities for local installa-

tion requirements.

NOTE: For Australia and New Zealand: Pipeline strainers

should be installed between the upstream shutoff valve and the

inlet of the backflow preventer.

It's important that this assembly be tested periodically in com-

pliance with local codes, but at least once per year or more as

service conditions warrant. If installed on a fire sprinkler sys-

tem, all mechanical checks, such as alarm checks and back-

flow preventers, should be flow tested and inspected internally

in accordance with NFPA 13 and NFPA 25.

RP/IS-757a/757aDCDA

Limited Warranty: Watts Regulator Company warrants each product to be free from defects

in material and workmanship under normal usage for a period of one year from the date of

original shipment. In the event of such defects within the warranty period, the Company will, at

its option, replace or recondition the product without charge. This shall constitute the sole and

exclusive remedy for breach of warranty, and the Company shall not be responsible for any inci-

dental, special or consequential damages, including without limitation, lost profits or the cost of

repairing or replacing other property which is damaged if this product does not work properly,

other costs resulting from labor charges, delays, vandalism, negligence, fouling caused by for-

eign material, damage from adverse water conditions, chemical, or any other circumstances

over which the Company has no control. This warranty shall be invalidated by any abuse, mis-

use, misapplication or improper installation of the product. THIS WARRANTY IS IN LIEU OF ALL

OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING ANY IMPLIED WARRANTIES OF

MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Any implied warranties that

are imposed by law are limited in duration to one year.

Some States do not allow limitations on how long an implied warranty lasts, and some States

do not allow the exclusion or limitation of incidental or consequential damages. Therefore the

above limitations may not apply to you. This Limited Warranty gives you specific legal rights, and

you may have other rights that vary from State to State. You should consult applicable state laws

to determine your rights.

Summary of content (4 pages)

PAGE 1
RP/IS-757a/757aDCDA Series 757a, 757aDCDA 757Na, 757NaDCDA Double Check Valve Assemblies Double Check Detector Assemblies Sizes: 21⁄2" – 6" (65 – 150mm) • Installation • Service • Repair Kits • Maintenance TM For field testing procedure, send for IS-TK-DL, IS-TK-9A, IS-TK-99E and IS-TK-99D. For other repair kits and service parts, send for PL-RP-BPD and F-RK-DC. For technical assistance, contact your local Watts representative.
PAGE 2
Basic Installation Instructions Guidelines Most field problems occur because dirt and debris present in the system at the time of installation becomes trapped in the #1 check. The system should be flushed before the backflow valve is installed. If the system is not flushed until after the backflow valve is installed, remove both check modules from the valve and open the inlet shutoff to allow water to flow for a sufficient time to flush debris from the water line.
PAGE 3
Test Procedures Double Check Valve Assemblies Test Check Valve No.1 Ball Type Test Valves Step 1: Ensure shutoff #1 is open, shutoff #2 is closed. C A Step 2: Connect high side hose to test cock #3, low side to test cock #2 and open both test cock #2 and test cock #3. Step 3: Open valve C, then open A to bleed air from the high side. close valve a, then open B to bleed low side. Close valve B. B Needle Valve Step 4: Connect vent hose loosely to test cock#1.
PAGE 4
757a, 757aDCDA Repair Kits Sleeve O-ring and Gasket Closure Sleeve Test Cock with O-ring Check Module O-ring Closure Sleeve E-clip Disc Elastomer First Check Module Second Check Module ORDERING NO. SIZE DISC 21⁄2" - 4" 6" EPDM EPDM MODEL ORDERING NO.