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Deringer 50G (RPDA-II)

Reduced Pressure Detector Backflow Preventer w/ OS&Y Gate Valves

SKU
Deringer 50G
MSRP: $14,279.00 MSRP: $14,279.00 Pro Price: $3,289.00 Pro Price: $3,289.00 Special Price $0.00
Price includes standard ground shipping.
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The Deringer 50G Reduced Pressure Detector Backflow Preventer w/ OS&Y Gate Valves 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 50 Approvals

main product photo

The Deringer 50G Reduced Pressure Detector Assemby 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.

Deringer 50G

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 125
IPS Groove for Steel Pipe: AWWA C606

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 50 (RPDA-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 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:

Rate of Flow Deringer 50G

Dimensions:

Deringer 50G measurements

Materials:

Valve Housing: 304 Stainless Steel
Valve Cover: 304 Stainless Steel
Bypass Spring: 302 Stainless Steel
RV Spring: 302 Stainless Steel
Non Wetted Bolts: Grade 8 Zinc Plated
Check Disks: Silicone
Wetted Fasteners: 18-8 Stainless Steel
Bypass Components: Lead Free Bronze
RV Housing: 304 Stainless Steel
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
RV Hose: Braided Stainless Steel Wire
Gate Valve: Stem includes tamper switch groove
Gate Valve: Serviceable inline
Gate Valve: AWWA C509/UL/FM resilient seat (OS&Y)
Gate Valve: Flanged End ANSI B16.1 Class 125
Coupling: Flexible Grooved UL/FM

Engineering Specifications

The Deringer 50GX Reduce Pressure Detector (RPDA-II) Valve shall utilize two independent Dual Action Check modules contained within a single valve housing constructed of entirely of 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). Gate valves shall utilize a stainless steel stem with a 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 utilize a single full access service port and a cover with an inline replaceable elastomer seal. Relief valve shall operate without the use of sliding seals and shall be constructed entirely of stainless steel. The bypass assembly shall include a meter registering gallons or cubic feet, a single check valve and test cocks. Assembly shall be serviceable without the use of special tools.

Maximum Relief Valve Discharge Rates

Deringer 50G Max Discharge

Deringer Specification Sheets

The Deringer 50G 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 50G Specification Sheet

Maintenance Instructions

The Deringer 40G/50G Maintenance Instructions provide step by step procedures for maintaining a 2 to 4 inch Deringer 40G/50G backflow preventer. A printable PDF document is available.

Deringer 40G/50G Maintenance Instructions

Maintenance Video - 2 to 4" Deringer 50

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.

Tamper Switch Instruction

Bypass Testing Instructions

30-50 Bypass Testing

True-Seal Check Modules

The True Seal Check Valve was designed to incorporate a poppet only motion during the check stroke and is used exclusively on the first check assembly on the Deringer RP and RPDA models and Magnum RP model. This design allows a more consistent pressure loss across the check valve which helps maintain a steady and continual closure of the Relief Valve.

  • 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.
True-Seal Check Modules

Poppet Action

Deringer and Magnum 40/50 Low Flow Poppet Action

Features:

  • 100% of check stroke is that of a poppet check
  • Consistent static sealing
  • Excellent resistant to fouling
  • Reliable check closure
  • Stable flow characteristics at ALL flow rates

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
Dual Action Check Module

Poppet Action

Low Flow 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.
High Swing Action

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
Bow Seal Access Cover

Tamper Resistant Test Cock

The Deringer tamper resistant 1/2" and 3/4" 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.

Deringer Tamper Resistant Test Cock

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.

Deringer Micro Bypass Assembly

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.

Deringer Bypass Angled Check Valve Image

Relief Valve

The Deringer 40/50 Relief Valve uses a stainless steel body, piston seal and stainless steel sensing line and has been designed to be the smallest and lightest Relief Valve in the industry. Unlike previous relief valve designs, the piston seal does not use the body of the relief valve to align itself properly when closing and opening and instead uses the guide pin on the piston. This will aid in making the Relief Valve resistant to build up and binding. All components of the relief valve are lead free and meet the SDWA requirements.

Relief Valve Image

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.

 

Download Warranty Information