Deringer 30 (DCDA-II)
Double Check Detector Backflow Preventer
The Deringer 30 Double Check Detector Backflow Preventer 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.
Deringer 30 Double Check Detector Assemblies prevent non-health hazard pollutants from entering a potable water supply system when backpressure and/or backsiphonage conditions occur. The Deringer 30 is used primarily on fire sprinkler systems when monitoring of unauthorized water use is required.

Maximum Working Pressure: 175psi (12.1 bar)
Temperature Range: 33 to 140 deg F (1 to 60 deg C)
Lead Free: 0.25% Maximum by Weight
End Connections:
Flange Adapters: ANSI B16.1 Class 126
IPS Groove for Steel Pipe: AWWA C607
Micro type-II Bypass Assembly
The type-II bypass on double check valve assemblies 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 on a Deringer 30 provides the EXACT same level of protection as a type-I bypass as well as some of the similarities and differences between the two.
Rate of Flow:

Dimensions:

Materials:
Valve Housing: 304 Stainless Steel
Valve Cover: 304 Stainless Steel
SOV Disks: EPDM/304SS
SOV Shafts: 304 Stainless Steel
Bypass Spring: 302 Stainless Steel
SOV Bearings: Teflon/Bronze
Non Wetted Bolts: Grade 8 Zinc Plated
Check Disks: Silicone
Wetted Fasteners: 18-8 Stainless Steel
Bypass Components: Lead Free Bronze
Check Springs: 17-7 Stainless Steel
Check Pins: 17-7/18-8 Stainless Steel
Check Seats: Noryl Polymer
O-Rings: Buna-N
Bypass Internals: ABS Polymer
Engineering Specifications
The Deringer 30(X) Double Check Detector Assembly (DCDA-II) shall utilize two independent Dual Action Check modules and two integral resiliently seated shut-off valves all of which shall be contained within a single rigid valve housing constructed entirely of 304 stainless steel. Both integral shutoff valves shall include pre-wired supervisory tamper switches contained within a weatherproof actuator housing approved for both indoor and outdoor use. 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. 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 seal. All bypass assembly components shall be leadfree and 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.
Deringer Specification Sheets
The Deringer 30 Specification Sheet includes information on valve characteristics, flow performance data, approval status and engineering specifications for all sizes. This file can be downloaded as a PDF and saved for future use.
Deringer 30 Specification Sheet
Maintenance Instructions
The Deringer 20/30 Maintenance Instructions provide step by step procedures for maintaining a 2 to 4 inch Deringer 20/30 backflow preventer. A printable PDF document and video of these instructions are both available.
Deringer 20/30 Maintenance Instructions
Maintenance Video - 2 to 4" Deringer 30
Tamper Switch Procedure
The Deringer Gear Box Tamper Switch Procedure provides a step by step instructions for positioning the wiring of the Deringer gear box for fire alarm protection. A printable PDF document of these instructions is available.
Gear Box Wiring Instructions
The Deringer Gear Box Wiring Installation Instructions provide step by step procedures for wiring the Deringer gear box for fire alarm protection. A printable PDF document of these instructions is available.
Indicator Flag Adjustment
The Indicator Flag Adjustment Instructions provides a step by step procedure for aligning the flag to fully open and fully close on the backflow preventor gear box. A printable PDF document of these instructions is available.
Bypass Testing Instructions
One Year Warranty
Backflow Direct warrants its product to be free from defects in material and workmanship under normal operating conditions for a period of one year from the date of original shipment. In the event of such defects within the warranty period, Backflow Direct retains the exclusive right to repair or replace (with a new or newly rebuilt product) the device or offer a full refund of the original purchase price at its sole discretion. Backflow Direct assumes no liability for replacement of inoperative products beyond the warranty period.
THE WARRANTIES AND REMEDIES CONTAINED HEREIN ARE EXCLUSIVE AND IN LIEU OF ALL OTHER WARRANTIES EXPRESS, IMPLIED, OR STATUTORY, INCLUDING ANY LIABILITY ARISING UNDER ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, STATUTORY OR OTHERWISE.
THE REMEDY ABOVE SHALL BE THE SOLE AND EXCLUSIVE REMEDY FOR ANY BREACH OF WARRANTY. Backflow Direct shall not be responsible for any special, consequential or incidental damages, including without limitation, repair costs or lost profits or property damage as a result of product malfunction or any other costs resulting from labor charges, delays, vandalism, negligence, fouling caused by foreign material, adverse water conditions or any other circumstances over which Backflow Direct has no control. SOME STATES DO NOT ALLOW THE EXCLUSION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, IN SUCH STATES, THE ABOVE LIMITATIONS MAY NOT APPLY.
This warranty shall be invalidated by any abuse, misuse, misapplication, improper installation or improper maintenance or alteration of the products.
To obtain warranty service, contact us for further instructions. When credit is issued it will be at the original purchase price.
Product Specific Warranty
1) NRS, OS&Y and/or any Gate Valves utilized as shut off valves on Backflow Direct products are covered by original manufacturer's warranty ONLY.
2) Reduced Pressure Principle Backflow Preventers (RP or RPDA) can and WILL discharge water. NEVER install an RP or RPDA in a location where any amount of discharge from the Relief Valve will cause property damage. For an indoor, pit, vault, mechanical room or enclosure installation of an RP or RPDA an auxiliary drain (SEPARATE AND INDEPENDENT of the Air Gap Assembly) is REQUIRED and MUST be properly sized for the Maximum Relief Valve Discharge Rate corresponding to the system/supply pressure. Backflow Direct shall not be responsible for any special, consequential or incidental damages, including without limitation, repair costs, lost profits, property damage, or any other costs resulting from labor charges, delays, vandalism, negligence, fouling caused by foreign material, adverse water conditions or any other circumstances, caused by lack of auxiliary drain, location of auxiliary drain or undersized auxiliary drain.
3) Air Gap Assembly will capture and evacuate light water discharge from the Relieve Valve caused by daily fluctuation in system/supply pressure. An Air Gap Assembly will NOT capture and evacuate the Maximum Relief Valve Discharge Rate caused by catastrophic valve or system failure. An auxiliary drain (separate and independent of the Air Gap Assembly) is REQUIRED and MUST be properly sized for the Maximum Relief Valve Discharge Rate. Backflow Direct shall not be responsible for any special, consequential or incidental damages, including without limitation, repair costs, lost profits, property damage, or any other costs resulting from labor charges, delays, vandalism, negligence, fouling caused by foreign material, adverse water conditions or any other circumstances, caused by lack of auxiliary drain, location of auxiliary drain or undersized auxiliary drain.
This warranty shall be invalidated by any abuse, misuse, misapplication, improper installation or improper maintenance or alteration of the products.
To obtain warranty service, contact us for further instructions. When credit is issued it will be at the original purchase price.