4" DERINGER 30GX (DCDA)
The 4" Deringer 30GX Double Check Detector Assembly prevents non-health hazard pollutants from entering a potable water supply system when backpressure and/or backsiphonage conditions occur. Used primarily on fire sprinkler systems when monitoring of unauthorized water use is required.
The smallest, lightest, most economical, best performing, and only all stainless steel backflow preventer. Period.
Approved in the Horizontal & Vertical Up Position.
Important Note: Install with FLEX Couplings or Flange Adapters Only. DO NOT use RIDGED Couplings!
Earliest ship date 3/12 due to high volume of orders.
MSRP:
$3,469.00Pro Price:
$2,479.00

The Deringer 30GX Double Check Detector Assembly prevents non-health hazard pollutants from entering a potable water supply system when backpressure and/or backsiphonage conditions occur. Used primarily on fire sprinkler systems when monitoring of unauthorized water use is required.

Micro type-II Bypass™ Assembly
The type-II bypass assembly is a new technology to the backflow industry and is used on Backflow Direct's Deringer 30 (DCDA-II).
As more manufacturers begin to utilize this technology it is only a matter of time before it’s widely used and is more commonly seen than the old type-I bypass assembly.
We created this video to provide a clear explanation on how the type-II bypass provides theEXACT same level of protection as a type-I bypass as well as some of the similarities and differences between the two.
Flow Performance

Measures & Materials

Engineering & Specifications
TheDeringer 30G(X) Double Check Detector Assembly 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. The bypass assembly shall include a meter registering either gallons or cubic feet, a single check valve and required test cocks. 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]
TECHNOLOGY
TopDual-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


Poppet Action
Features:
- 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
Swing Action
Features:
- 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.

Micro-Bypass™ Assembly
The Deringer 30/50 Micro Bypass™ Assembly is a type II bypass that utilizes an angled check valve and includes a standard 5/8 X 3/4 water meter for water use detection. It is the shortest, lightest and smallest bypass in the industry and the same bypass is used on all size Deringer 30/50 models. Constructed of lead free bronze, the micro bypass assembly meets all SDWA lead free standards.

Bypass-Angled Check Valve
The bypass angled check valve has many features shown in the graphic below that are fundamental to creating the shortest, lightest and smallest bypass in the industry.
