Safety Vacuum Release Systems SVRS

Understanding SVRS:

A Safety Vacuum Release System (SVRS) is designed to disable a pool pump's suction if a body or object becomes trapped against the suction outlet. It achieves this by introducing air into the pump or shutting down the pump motor when it detects a sudden increase in vacuum pressure.

Installation and Function:

An SVRS is typically easy to install in pools, spas, or water features, provided basic installation guidelines are followed. These devices can be integrated into the pump motor, installed as a separate controller, mounted on the suction pipe, or even be as simple as replacing the pump pot drain plug. Installation must comply with the ASME/ANSI A112.19.8 standard, including an approved VGB drain cover. SVRS devices are generally compatible with pumps ranging from 0.5 to 10.0 horsepower.

SVRS units consist of nine key components: cap, base, piston, piston O-ring, cap O-ring, base O-ring, two screws, a spring, and lubrication (if needed). These parts work together to quickly prevent entrapment incidents by disrupting suction.

Types of SVRS:

There are two primary types of SVRS: electrical and mechanical. Electrical systems momentarily shut off the pump motor to relieve entrapment, with automatic or manual restarts depending on the system. Mechanical SVRS units use a piston-driven valve to introduce air into the pump and break suction.

When a high vacuum occurs due to entrapment, mechanical SVRS systems allow air to enter the suction side of the pump. This process compresses the piston spring, which moves the O-ring to open air passages, causing the pump to lose prime and release the trapped object. The system resets automatically or manually after entrapment is resolved.

Installation Guidelines:

SVRS installation varies by manufacturer. To minimize vacuum pressure and ensure accurate responses, some manufacturers recommend installing the SVRS on the main drain line only, avoiding vacuum from the skimmer. Placement between 5 feet and 18 inches from the pump is often ideal, though some units are designed to attach directly to the pump.

Electrical SVRS installation requires drilling a small hole in the suction-side plumbing and connecting the pipe to the SVRS using a small tube. It's also crucial to check local codes and ensure the unit is properly bonded or grounded.

Larger pumps or more complex hydraulic systems create higher vacuum levels, so it's essential to select an SVRS appropriately sized for the pool and pump. In some cases, downsizing the pump may be necessary to keep vacuum levels manageable, with most SVRS units recommended for settings under 18 inches of mercury.

Testing and Maintenance:

To ensure proper functionality, SVRS units should be tested three times upon installation. Popular testing methods include physically blocking the drain with a pole-guided mat or using a ball valve to simulate a blockage. Successful tests will cause the pump to either shut off or lose prime, with air entering the pump pot.

Testing should be performed monthly during swim season to maintain safety. Manufacturers typically include user manuals detailing testing procedures and troubleshooting steps, along with providing technical support for service technicians or end users.