Double Check Valves Plumber in Minneapolis, St Paul, Twin Cities

Duplex-valveMetro Testing installs, tests, and repairs Double Check Valves all across the Minneapolis / St Paul Metro area and across all of Minnesota.

Call us at 612-221-5888 to get help with your Double Check Valve backflow preventer.

For underground and indoor installations, the double check valve is an excellent choice. The device consists of an inlet shutoff valve, an outlet shutoff valve, 4 test cocks and a couple of independently operating spring-loaded check valves usually within a singular valve chassis. The double check valve is the most common certified backflow prevention device recommended for use in in-line or in parallel with the piping of the water system as well as for underground installations

Installation – Minneapolis, St Paul, Twin Cities

The double check valve may be installed above or underground but it cannot be used for chemigation purposes. The device can be installed vertically and horizontally with the latter being the preferred mode. This backflow preventer can be used in areas where there is a threat of back-pressure or back-siphoning.


During testing of the double check valve assembly, the tester first obtains a reading on the first check valve and then another reading on the 2nd valve. In most scenarios, the technician may continue on to test the second check valve after the 1st check valve, even if the first check valve holds at a value below the standard 1.0 psi. The exception to the rule is when the reading on the number one check valve is less than 1.0 psi and there is the present of a leak on the number 1 valve. If this is the case, repairs need to be done first prior to moving on to the second check valve.

Annual Testing

Annual testing is necessary to determine correct operation of you double check valve assembly. Backflow preventers do not show any physical signs of damage so there is a risk that one may already be defective even if the physical appearance looks normal.

Overhaul or Repair of Double Check Valve

Double check valves can be overhauled using rubber repair kits. Rubber components, seals and check modules should be overhauled only by a certified plumber. Replacement of the entire assembly rarely is necessary. However, doing so is a fairly straightforward process. This is done by disconnecting the assembly section at its unions, and duplicate the section using a brand new double check valve along with pipes and fittings. Lastly, the assembly is reconnected and then tested for signs of leakage. Depending on the local code, an inspection may be needed.

If you are in the Twin Cities metro and need a good double check valve plumber for testing, installing, repair or overhaul, give us a call.