Backflow Reference Manual - Wilkins

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975 / 975A / 975XL / 975XL2 / 975XL MS


1/4", 3/8", 1/2", 3/4", 1", 1 1/4",1 1/2", 2", 2 1/2", 3", 4", 6", 8", 10"


This is a reduced pressure assembly. Production began in 1990. Starting in 2004 in sizes 3/8" and 1/2" a stainless steel body assembly was produced. The checks are similar to the one used in the 950 design. The 3/4"-2" size is a wye pattern poppet style check design with the disc holders made of a glass filled noryl. The relief valve has an internal relief valve sensing line. The body is constructed of bronze. In 2010 a 975XL2 was introduced which is made of lead free bronze. There are three versions of check seats available. The 975 version was discontinued in 1992 and had a non-replaceable check seat. The model 975A was discontinued in 1992 and had a replaceable bronze check seat. The model 975XL began production in 1993 and had a replaceable check seat made of glass filled noryl. A seat removal tool was needed to change the seats. The check discs in the 975XL were changed to silicon rubber. In 2001 the 975XL was made available with a stainless steel body in sizes 3/8"-1/2". The relief valve seat is replaceable. Checks and relief springs are not contained when the covers are removed. The 2 1/2"-10" was produced from 1990-2004. The 2 1/2"-10" size has a fused epoxy coated cast iron check body. The check seats are replaceable and the check springs are contained when the cover is removed. The relief valve is mounted to the check body and can be removed. The relief valve is a bronze bodied unit with an internal sensing line. The relief valve spring is contained when the cover is removed and the relief valve seat is replaceable. In 1995 the 975 XLMS was introduced. It is the same basic design as the 975 XL except the relief valve contains a 24 volt monitor switch which can send a signal when the relief valve is opened. The 975 XLBMS is a battery operated version.


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.