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, abdominal 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 atmospheric vent provides a visual indication of failure in the event that the downstream check fails and system backpressure exceeds the supply pressure.

Tested and certified by NSF. The Watts SD3-FN Dual Check Valve has been tested and certified by NSF to meet NSF/ANSI standard 61 Annex G. This certification demonstrates that this valve meets the lead-free qualifications.

Specifications:

• Certified to ANSI/NSF Standard 18
• 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

Note:The wetted surface of this product contacted by consumable water contains less than 0.25% of lead by weight.