Pool Safety Council
Consumer Product Safety Commission
National Swimming Pool Foundation
The Zac Foundation
Safety Vacuum Release Systems
A phrase originally coined by Vac-Alert to describe their product, Safety Vacuum Release System (SVRS) is now broadened in meaning to cover all main drain entrapment release devices.
These products provide a secondary line of defense against drain suction entrapment. If a drain cover becomes blocked, and there is no SVRS product in the system, the pump will continue to create suction and will not release the blockage (entrapment).
The purpose of an SVRS product is to release the entrapment. There are currently two forms of SVRS products. One form allows for an opening in the plumbing line, releasing the entrapment. The other form electronically turns off the pump, releasing the entrapment. Both forms work well provided there is not a checkvalve in line that will not release the vacuum. If the SVRS does not vent the plumbing line, a checkvalve anywhere in the main plumbing line, suction or pressure will prevent the vacuum from going away. A downstream checkvalve can be defeated by the SVRS locking, and opening to atmosphere. Such is the case with the Vac-Alert and the Hayward Stratum.
SVRS performance can be affected by a hydrostatic relief valve. Please check every installation with a hydroststic relief valve by covering the drain several times. If you have any concerns, remove the hydrostatic relief valve from the pool. Place it in the equipment room with specific instructions that it must be reinstalled prior to draining the pool.
The first SVRS developed was the Stingl Switch. Adjustable by vacuum the Stingl Switch works by powering down the suction pump when the vacuum at the pump exceeds the set value. Shortly after the Vac-Alert came out on the market. The Vac-Alert is mechanical in design. It has an adjustable vacuum setting that when tripped immediately fills the pump with air. Additionally it ventilates the
vacuum line, Immediately releasing the obstruction. In 2007 the Virginia Graeme Baker act was passed, requiring this type of device on all single drain commercial pools. Subsequent to it's passing, Hayward announced the Stratum, Pentair announced an SVRS feature to their Intelli VS pump series, Vacless introduced their release device into the pool market, Emotron announced their product, and AO Smith introduced the Guardian. By clicking on the links below you will open a page showing my opinions of the strengths and weaknesses of each of these products. Additionally there is a comparison table rating the various "SVRS" products.
VGB tested and approved SVRS Products