Backflow Testing & Maintenance Services

Pro Service Plumbing is a licensed & insured certified backflow installation and maintenance company. You can feel confident working with a team that is committed to getting the job done right the first time, and on time, everytime. We provide affordable backflow services, and you can have confidence in our AWWA Certified technicians. This qualifies us as one of the few companies able to test all backflow assemblies throughout South Florida.


Vacuum Breaker


The Atmospheric Vacuum Breaker is one of the simplest and most cost-effective devices available. The mechanical device prevents against backsiphonage, but not against backpressure. A float inside the device is lifted by water pressure. When the float is lifted, an internal disc seals. When the water supply is shut off, the disc drops down and opens downstream piping to atmospheric pressure. It must be installed 6″ higher than all downstream piping and cannot have any shutoff valves downstream from the installation point


Vacuum Breaker


The Pressure Vacuum Breaker, unlike the Atmospheric Vacuum Breaker, can be used on a system that is under continuous pressure. It is effective against backsiphonage situations, but not backpressure. A springloaded float device and two test cocks make the unit a bit more sophisticated than its cousin, the Atmospheric Vacuum Breaker.

The Pressure Vacuum Breaker must be installed 12″ above the highest point that occurs downstream, If a head is 3′ off the ground, the backflow must be installed 1′ higher than the head.

Double Check

Dual Check


The dual check is manufactured with two independent 1psi loaded check valves. It can be used to prevent against backsiphonage and backpressure. However, it should only be used when protecting against non-hazardous contaminants. The unit does not have a shutoff or test port installed at time of manufacture and cannot typically be repaired or tested while inline. Given its comparatively small design (compared t o t h e double check) its capacity is typically less. Dual checks are designed to meet a rated flow. Because of its size, its rated flow (similar to maximum flow capacity) is 15gpm. Unlike the double check below, the unit is held to only one standard of manufacturing: the American Society of Sanitary Engineering (ASSE), Chapman added. Depending upon local municipalities, dual checks are allowed in some areas.


Double check devices are manufactured with two individual spring-loaded check valves with a minimum of 1psi that presses the check valve closed. Effective against backflow and backsiphonage, it’s recommended for low hazard situations. Two ball valves protect against debris. Four ports are installed during manufacturing to allow for maintenance and testing. The double check is much larger in size than the dual check and has a rated flow of 30 gpm. It can be tested and repaired inline. Installation is commonly done in a meter box underground or in the homeowner’s basement. The double check must meet ASSE and USC-FCCCHR standards and also requires routine testing, once at the time of installation and once every year after installation.

Reduced Pressure

Zone Assembly


Referred to as an RPZ, this unit offers the most sophisticated level of contamination protection from backsiphonage and backflow. Even though an RPZ unit looks similar to a double check device, a few defining features distinguish the two.

The RPZ has two independent check valves. However, the first has a minimum spring-loaded pressure of 5psi and the second has a minimum of 1psi. Furthermore, the RPZ has an atmospheric relief vent mounted below the two double checks. Because it is relatively large, like the double check, it will cause flow loss and a pressure drop, explained Mantelli.

The double check is like a sealed piece of pipe and there is no way to tell if a problem exists unless it is disassembled or tested. However, an RPZ has a pressure-sensitive relief valve; it will leak water to let you know there is a problem. “The discharge does not mean the device is defective, it is designed to give an indication that cleaning or maintenance is needed,” Chapman added.

RPZs must be installed at least 12″ above grade. Local municipalities always have the last say on what type of backflow device can be installed. However, in many instances the water purveyors will allow a more sophisticated device than what is required by code. “On Long Island, the water purveyor will often allow a RPZ even though a double check is code because an RPZ offers even greater protection,” Chapman said.