4" DERINGER 20G (DC)
The 4" Deringer 20G Double Check prevents non-health hazard pollutants from entering a potable water supply system when backpressure and/or backsiphonage conditions occur.
The smallest, lightest, most economical, best performing, and only all stainless steel backflow preventer. Period.
Important Note: Install with FLEX Couplings or Flange Adapters Only. DO NOT use RIDGED Couplings!
This valve is made to order. Lead time is 4-5 business days + shipping time.
The Deringer 20G(X) Double Check Valve Assembly is designed to prevent non-health hazard pollutants from entering the potable water supply system caused by backpressure and/or backsiphonage conditions.
Measures & Materials
Engineering & Specifications
The Deringer 20G(X) Double Check Valve shall utilize two independent Dual Action Check modules contained within a single valve housing constructed entirely of 304 stainless steel. Dual Action Check modules shall operate as a "poppet style" check under low flow conditions, operate as a "swing style" check under high flow conditions and utilize replaceable silicone elastomer sealing discs. Valve assembly shall include two resiliently seated and inline serviceable AWWA C509 gate valves of type outside yoke and stem (OS&Y). Both gate valves shall include a stainless steel stem with pre-machined groove for installation of supervisory tamper switches. Assembly test cocks shall be handle-less and operate via a tamper resistant actuator. Assembly shall have a single full access service port and cover with an "inline" replaceable elastomer cover seal. Assembly shall be serviceable without special tools and approved for both horizontal and vertical applications.
Retrofit Spool Program
The Backflow Direct Retrofit Program is the easiest spool ordering process in the industry!
Simply go to our online Retrofit Spool Form and submit a few pieces of needed information. Backflow Direct will take the information provided and create a CAD drawing of the completed retrofit package along with a quote for you to review.
When you are ready to order, simply confirm by email and BackFlow Direct will start your order. It really is THAT easy!
BackFlow Direct's retrofit program video provides an easy to understand demonstration of the ordering process from start to finish. Please feel free to contact us with any questions at [email protected]
Dual-Action™ Check Modules
The Patented Dual-Action Check™ (US8875733) is the core technology behind the superior performance of Deringer Backflow Prevention Product Line. The Dual-Action Check™ combines all of the best features of industry standard “poppet” checks and “swing” checks into a single high performance check module.
- Light weight engineered polymer components.
- Modular for easy removal of complete check from body.
- Easily disconnect spring tension for safe check servicing.
- Replaceable Silicone Rubber Elastomer Disk.
- Excellent resistance to fouling
- Initial 25% of check stroke is that of a poppet check.
- Consistent static sealing
- Excellent resistant to fouling
- Reliable check closure
- Stable flow characteristics at lower flow rates
- Final 75% of check stroke is that of a swing check.
- Minimal friction loss at high flow rates.
- More linear flow path water through valve.
Bow-Seal™ Full Access Cover
The Patented Bow-Seal™ Full Access Cover (US8844562) is pre-formed to cylindrical shape friendly to high fluid pressure. This allows the cover to be much thinner and lighter than traditional flat covers while still providing FULL and EASY access to Dual Action™ Check Modules.
Additional features include:
- Light weight
- Simple removal
- No sliding seals
- Full access to valve internals
- No cumbersome and heavy couplings
Tamper Resistant Test Cock
The Deringer tamper resistant ½” and ¾” ball valves are the first handle-less test cocks found on large diameter backflow devices in the industry. The top of the valve actuation stem has a unique shape that uses an independent custom wrench to open and close test cocks. All test cocks are lead free and meet the SDWA requirements.