Backflow Reference Manual - SMR

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711 / 711S


1 1/4", 1 1/2", 2"


The Model 711 is a pressure vacuum breaker. It was produced from approximately 1955-1977. It was produced originally under the SMR name and later sold to the Neptune Co. who also produced it. Either name may be on the unit. The assembly was originally produced without an air inlet spring. A field modification was introduced in 1978 to give it a one pound minimum air inlet loading. The S designation on the model number means the air inlet is spring loaded. The body is made of bronze. Check seats are cast in the body and are not replaceable. The check spring was contained when the bonnet was removed.


Common repair parts are a very small subset of the 10,000 plus items BAVCO stocks. Please feel free to contact us direct at 800-458-3492 for pricing on items not listed or backflow prevention devices.