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RP/IS-909/909RPDA

Watts 909 OSY shown

Designed for inline servicing

IMPORTANT:

 Inquire with governing authorities for local installa-

tion requirements.

 

NOTICE

For 

Australia

 and 

New Zealand

, line strainers should be installed 

between the upstream shutoff valve and the inlet of the backflow pre-

venter.
Its important that this device be tested periodically in compliance 

with local codes, but at least once per year or more as service con-

ditions warrant. If installed on a fire sprinkler system, all mechanical 

checks, such as alarm checks and backflow preventers, should be 

flow tested and inspected internally in accordance with NFPA 13 

and NFPA 25.

Testing

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

IS-TK-9A, IS-TK-99E and IS-TK-99D.
For repair kits and service parts, reference PL-RP-BPD at  

www.watts.com
For technical assistance, contact your local Watts 

representative.

Installation, Maintenance, & Repair 

Series 909, LF909, 909RPDA, LF909RPDA

Reduced Pressure Zone Assemblies 

Reduced Pressure Detector Assemblies

Sizes: 2

1

2

" – 10" (65 – 250mm)

Local building or plumbing codes may require modifications to 

the information provided.  You are required to consult the local 

building and plumbing codes prior to installation.  If this informa-

tion is not consistent with local building or plumbing codes, the 

local codes should be followed.

Need for Periodic Inspection/Maintenance:

  This product 

must be tested periodically in compliance with local codes, but 

at least once per year or more as service conditions warrant.  

Corrosive water conditions, and/or unauthorized adjustments 

or repair could render the product ineffective for the service in-

tended.  Regular checking and cleaning of the product’s internal 

components helps assure maximum life and proper product 

function. 

WARNING

!

Read this Manual BEFORE using this equipment.
Failure to read and follow all safety and use information 

can result in death, serious personal injury, property 

damage, or damage to the equipment.
Keep this Manual for future reference.

Basic Installation Instructions

NOTICE

The flange gasket bolts for the gate valves should be re tight ened 

during in stal la tion as the bolts may have loos ened due to stor age 

and  ship ping.

High Capacity Relief Series: 

Location and Installation Considerations

  1.  Backflow preventers must be installed in high-visibility locations 

in order to allow for immediate notice of telltale discharge or 

other malfunction. This location should also facilitate testing and 

ser vic ing, and protect against freezing and vandalism.

  2.  Installing a backflow preventer in a pit or vault is not rec om-

mend ed. However, if this becomes necessary, Watts highly rec-

om mends that a licensed journeyman tradesperson, who is rec-

ognized by the authority having jurisdiction, be consulted to 

ensure that all local codes and required safety provisions are 

met. An air gap below the relief port must be maintained so as 

to avoid flooding and submersion of the assembly, which may 

lead to a cross connection. *Please refer to Figure No. 1 for fur-

ther information.

  3.  A strainer should be installed ahead of the backflow preventer to 

protect all internal components from unnecessary fouling.

 

CAUTION

!

Do not install a strainer ahead of the backflow preventer on seldom-

used, emergency water lines (i.e. fire sprinkler lines). The strainer 

mesh could potentially become clogged with debris present in the 

water and cause water blockage during an emer gen cy.
  4.  Normal discharge and nuisance spitting are accommodated by 

the use of a Watts air gap fitting and a fabricated indirect waste 

line. Floor drains of the same size MUST be provided in case of 

excessive discharge. *Please refer to Figure No. 1 and Figure 

No. 2 for further in for ma tion.

  5.  When a 909/LF909 Series backflow preventer is installed for 

dead-end service applications. (i.e. boiler feed lines, cooling 

tower makeup or other equip ment with periodic flow require-

ments), discharge from the relief vent may occur due to water 

supply pressure fluctuation during static no-flow con di tions. A 

check valve may be required ahead of the backflow preventer. 

*Please see “Troubleshooting”, Page 7, prior to installation.

Summary of Contents for LF909

Page 1: ...this Manual for future reference Basic Installation Instructions NOTICE The flange gasket bolts for the gate valves should be re tight ened during in stal la tion as the bolts may have loos ened due to stor age and ship ping High Capacity Relief Series Location and Installation Considerations 1 Backflow preventers must be installed in high visibility locations in order to allow for immediate notic...

Page 2: ...n its proper order The gate valve with the test cock is to be mounted on the inlet side of the backflow preventer The test cock must be on the inlet side of the wedge Please see above Failure to reassemble correctly will result in possible water damage due to excessive discharge from the relief port vent and possible malfunction of the backflow pre venter 8 Installation procedures must comply with...

Page 3: ...e is filled open the downstream shutoff slowly and fill the water supply system This is necessary to avoid water hammer or shock damage G The installation of a Watts air gap with the drain line terminating above a floor drain will handle any normal discharge or nuisance spitting through the relief valve However floor drain size may need to be designed to prevent water damage caused by a cat astrop...

Page 4: ...sh Print Head wait then Push Start Test 7 Open VA then slowly open VB no more than 1 4 turn When relief valve drips push the hold button for 2 seconds Record reading must be 2 psid or more Push Stop Test 8 Close VA and VB Test No 2 Test No 2 Check Valve 9 Install bypass hose between VA and TC 4 Open VA then bleed air by loosening hose connection at TC 4 Tighten hose connection Close VA Push Start ...

Page 5: ...two spring retainers and the stem The spring re tainers are not to be removed for servicing If there is a need to re place the spring spring retainer or stem an assembled module must be obtained from the factory These modules are not interchangeable be sure to replace the first check with a first check mod ule and the second check with a second check module 6 To replace the disc on sizes 21 2 4 65...

Page 6: ...embly 5 Removal of the bottom plug and spring assembly During nor mal field service there is no need to remove the bottom plug spring assembly other than inspection It can be removed by simply unscrewing with a large pipe wrench CAUTION The spring as retained on the bottom plug is highly loaded NO attempt should be made in the field to remove the spring For replacement a complete bottom plug assem...

Page 7: ...place relief valve seat or inlet cover Electrically ground the piping system and or electri cally isolate the device with plastic pipe immediately upstream and down stream of the device B 6 Valve improperly reassembled B 6 If valve is dis as sem bled during installation caution must be exercised to install check springs in their proper location C Valve exhibits high pressure drop C 1 Fouled strain...

Page 8: ...ost 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 foreign 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 misuse misapplication improper insta...

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