Frequently Asked Questions
Q: Can the Deringer be installed vertically?
A: DC and DCDA-II Deringers (20/20G and 30/30G) can be installed vertically and only vertical up, not down. RP and RPDA-II Deringers (40/40G and 50/50G) cannot be installed vertically, only horizontally. The top lid and nameplate of the device must be pointing up in a horizontal application. You cannot rotate the device on its access.
Q: What is Deringer weight and lay length?
A: You can find dimensions and weight on the product page, and more detailed information on the Specification Sheet under Literature Download on each product page. Spec sheets are also on our Resources page. Deringers range from about 18 inches up to 45 inches. The smallest Deringer weighs just 38 pounds and the largest is over 400 pounds, that's an 8" with OS&Y gate valves.
Q: Where can I find Deringer Maintenance or Repair instructions?
A: On each product page under Literature Download, find maintenance videos, repair instructions, Indicator Flag Adjustment Instructions, Gear Box Wiring Instructions, Tamper Switch Procedure, and more. Our Resources page also contains many helpful videos and documents.
Q: What is a Type-II Bypass?
A: We get this question all the time, so we wrote a blog to explain. We also have videos on out YouTube channel to explain DCDA-II and RPDA-II, and show you how to fill out a test report for the type-II bypass.
Q: What does the "X" mean on Deringer models?
A: "X" stands for Xtreme. Deringer Xtreme models have a larger body and check valves than the connection size, this gives you a huge savings in pressure loss. For example, the 4” Deringer 20X has a 4” connection size, but it has the body and check valves of the 6” Deringer 20 backflow preventer. Learn more in this blog.
Q: Is the Deringer USC/ASSE Approved?
A: All Deringer models are USC approved. Deringer 20/40s are also ASSE Approved. Find a full list of approvals on our Resources page or view the product spec sheet.
Q: Can I remove the wires on the Deringer?
A: If you don't need tamper switches, then yes, you can snip off the wires. They are not needed for the functioning of the device and if you don't need them, they hang off the device, which doesn't look great.
Q: Can I add a bypass to convert one Deringer model to another?
A: No, a bypass can not be added to a device in field. You cannot convert a Deringer 20 to a 30 or a 40 to a 50. You would have to return the 20 or 40 and purchase a 30 or a 50.
Q: Where can I find the Magnum product line?
A: We no longer offer the Magnum product line. Magnum Backflow Preventers were developed for irrigation and domestic. We now only carry the Deringer.