Manual

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
JobName
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Contractor
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JobLocation
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 Approval
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Engineer
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 Contractor’sP.O.No.
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Approval
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Representative
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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.