Watts LF7 User Manual

For Light Commercial and Residential Applications

ES-LF7

Job Name

Job Location

Engineer

Approval

LEAD FREE

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*

Series LF7

Dual Check Valves

LF7 Sizes: 11⁄4" (32mm)
LF7C Sizes:

Series LF7 Dual Check Valves are designed for non-health
hazard residential water system containment and continu­ous pressure applications, such as the drinking water supply
service entrance or individual outlets. Series LF7 uses two
compact replaceable check modules and is installed imme­diately downstream of the residential water meter. The LF7
features Lead Free* construction to comply with Lead Free*
installation requirements.

Features

•   Can be installed vertically or horizontally

•   Available with combination of inlet/outlet sizes, types or 

thread and end connection including retrofit compression
fittings and hose connections

•   Can be installed in many piping configurations and with a 

wide range of meter horns, copper setters and meter boxes

Specifications

The dual check backflow preventer shall meet the domestic

requirements of ANSI/ASSE Standard 1024, and bear the 
seal of approval. It shall have a cast body and include not

less than one union, with the union nut drilled to accept a
tamper-proofing lock wire. A brass identification tag indicat­ing direction of flow shall be securely attached to the valve
body by corrosion-resistant mechanical fasteners. The Lead
Free* Dual Check Valve shall comply with state codes and
standards, where applicable, requiring reduced lead content.
The dual check shall be Watts Series LF7. (Please select the
model best suited to your application.)

3

⁄8" (10mm)

Contractor

Approval

Contractor’s P.O. No.

Representative

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LF7

Standards

Complies with Buy America Act (BAA 1933) and The Ameri­can Recovery and Reinvestment Act (ARRA 2009).

Series 7: Inlet/Outlet Connections – Types available, ordering 

code, sizes available.

CONNECTION CONNECTION SIZES AVAILABLE
TYPE CODE

in. mm

National Pipe Thread Female 2
National Pipe Thread Male 3 1
Meter Thread Female* 4 1
Female Meter Thread (Swivel) 10 1

* When ordering Series LF7 Valves with Meter Thread Con­nections, be sure to order connection size one size

larger than meter thread. Example:

3

⁄8 , 11⁄4 10, 32

1

⁄4 32

1

⁄4 32

1

⁄4 32

Pressure - Temperature

Temperature Range: 33˚F – 180˚F (0.5˚C-82˚C) continuous
Maximum Working Pressure: 150psi (10.3 bar)

Meter Size Order

  1" (25mm)  1

Approvals

B64.6

1024

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

1

⁄4" (32mm)

Materials

•   Body:  LF7 Lead Free* cast copper silicon alloy

•   Check Modules: Durable plastic

•   Discs: Silicone 

•   Seals: Buna-N 

•   Springs: Stainless steel 

LF7C chrome-nickel plated Lead Free* cast copper
silicon alloy

Capacity

3

kPa psi

103 15

83 12

62 9

∆P

41 6

21 3

0 0

⁄8" (10mm) 7C

0 1 2 3 4 5 6 7 8 9 10 gpm

3.8 7.8 11.4 15.2 19.0 22.8 26.6 30.4 34.2 38 lpm

FLOW

11⁄4" (32mm) LF7

11⁄4"

0 5 10 15 20 25 30 35 gpm
19 38 57 76 95 114 133 lpm

FLOW

∆P

kPa psi

103 15

69 10

35 5

0 0

Dimensions - Weight

B

A

MODEL SIZE (DN) DIMENSIONS WEIGHT

A B

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

LF7
LF7C
LF7 10-U2 1
LF7 10-U3 1
LF7 4-U2 1

3

⁄8 10 27⁄8 73 11⁄4 32 .69 0.31

3

⁄8 10 27⁄8 73 11⁄4 32 .69 0.31

1

⁄4 32 49⁄16 116 21⁄4 57 1.80 0.82

1

⁄4 32 51⁄4 136 21⁄4 57 1.80 0.82

1

⁄4 32 45⁄16 110 21⁄4 57 1.50 0.68

A Watts Water Technologies Company

USA: Tel. [phone] • Fax: [phone] • www.watts.com

Canada: Tel. [phone] • Fax: [phone] • www.watts.ca

ES-LF7   1322    © 2013 Watts