Specification

For Non-Health Applications
ES-9DM3/M2
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IMPORTANT: INQUIRE WITH GOVERNING AUTHORITIES
FOR LOCAL INSTALLATION REQUIREMENTS
Series 9D
Dual Check Valve with
Intermediate Atmospheric Vent
Sizes:
1
⁄2"M3 (15mm),
3
⁄4"M2 (20mm)
Series 9D is specially made for smaller supply lines and ideally
suited for laboratory equipment, processing tanks, sterilizers,
dairy equipment and similar applications. It is particularly recom-
mended for boiler feed lines to prevent backflow when supply
pressure falls below system pressure.
Series 9D is suitable for use on hot or cold water and can be
used under continuous pressure. It features a primary check
valve utilizing a rubber disc seating against a mating rubber part
to ensure tight closing. A secondary check valve utilizes a rub-
ber disc-to-metal seating. In the event of fouling of the down-
stream check valve, leakage would be vented to atmosphere
through the vent port thereby safeguarding the potable water
system. Construction is brass body with stainless steel working
parts, integral strainer and durable rubber discs. Female union
inlet and outlet connections. Sizes
1
⁄2" (15mm) and
3
⁄4" (20mm).
Drain is
1
⁄2" (15mm) thread connection.
Features
• True line-sized construction allows the check modules to
open further allowing dirt and debris to pass more freely
reducing check fouling
• Stainless steel internal parts
• Maximum flow at low pressure drop
• Furnished with union connections to facilitate removal and
replacement for maintenance
• Compact for economy combined with performance
• Design simplicity for easy maintenance
• Can be installed vertically or horizontally
Specifications
For Backflow Preventers with Atmospheric vents
A Dual Check Valve with Atmospheric Vent shall be installed at
referenced cross-connections. Valve shall feature stainless steel
and rubber internals protected by an integral strainer. Primary
check shall be rubber to rubber seated, backed by the secondary
check with rubber to metal seating. The device shall be ASSE
approved under Std. 1012 and shall be a Watts Series 9D.
Available Models
Suffix:
S – for
1
⁄2" (15mm) union end solder connections.
SC – for satin chrome finish
LU – less union
9D-M2
May also be installed vertically
Union outlet
Secondary
check valve
Rugged mesh
stainless strainer screen
Primary
check valve
Vent and drain
connections
Brass body construction and stainless working parts throughout
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.