Technical Specifications

Watts No. SD-3
Backflow Preventer for
Carbonated Beverage Machines
Sizes:
1
⁄4",
3
⁄8" (8, 10mm)
Series SD3 is a dual check with atmospheric port designed
for the protection of the water supply from carbon dioxide
gas and carbonated water. These substances can flow from
post-mix beverage systems and are very acidic. If the acidic
water comes in contact with copper tubing or copper pipe, it
will cause the leaching of copper salts into the water supply.
The dissolved copper if ingested can cause nausea, abdomi-
nal pain, and in some cases vomiting. The SD3 prevents the
reverse flow of potentially contaminated water into the potable
water supply due to back pressure backflow and is used for
continuous or intermittent pressure conditions. The SD3 atmo-
spheric vent provides a visual indication of failure in the event
that the downstream check fails and system backpressure
exceeds the supply pressure.
The Watts SD3 is recommended for use on Post-Mix
Carbonated Beverage Equipment and dispensing equipment
for tea and coffee.
Features
• Certified to ANSI/NSF Standard 18, Manual Food and
Beverage Dispensing Equipment
• ASSE 1022 Approved Dual Check with Atmospheric Vent
• 316 stainless steel body for corrosion resistance
• All rubber compounds comply with FDA food
additive regulations
• Streamlined body design minimizes pressure loss
and cavitation
• A wide variety of custom end connections are available
• Endurance tested for more than 500,000 pumping cycle
• Atmospheric port provides visual indication of failure of the
second check
• Wye pattern strainer model for water supply installations
Available Models
1
⁄4" (8mm) SD3-MN: Male NPT
3
⁄8" (10mm) SD3-MN: Male NPT
1
⁄4" (8mm) SD3-FN: Female NPT
3
⁄8" (10mm) SD3-FN: Female NPT
1
⁄4" (8mm) SD3-MF: SAE Male Flare
3
⁄8" (10mm) SD3-MF: SAE Male Flare
3
⁄8" (10mm) SD3-MF-LS: SAE Male Flare, less strainer
Note: The above connections are available as outlet connec-
tions only. Strainer inlet connection is always Female NPT.
Specifications
Backflow preventer body and adapters are of 316 stainless
steel construction and all rubber components comply with
FDA food additive regulations. All materials in contact with the
potable water are in compliance with the requirements of the
Safe Drinking Water Act, Public Law 93-523, National Interim
Primary Drinking Water Regulations. Strainer manufactured
from NSF approved acetal plastic.
For Non-Health Hazard Applications
ES-SD3
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LEAD FREE
*
*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 with-
out prior notice and without incurring any obligation to make such changes and modifications on Watts products previously or subsequently sold.
B64.3
The information contained herein is not intended to replace the
full product installation and safety information available or the
experience of a trained product installer. You are required to
thoroughly read all installation instructions and product safety
information before beginning the installation of this product.
NOTICE