Backflow Reference Manual - Watts

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909 / LF909 / 909 M1 / LF909M1


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


Model 909 is a reduced pressure backflow assembly. Production began in 1979. The 3/4"-3" size body is constructed of bronze. In 2010 a LF909 model was produced that utilized a lead free bronze. The 2 1/2"-10" size check body is cast iron with a fused epoxy coating. The 2 1/2" and 3" were available in bronze and cast iron. Watts also has a hot water option available in the 3/4"-2" which is good up to 210° F. This is designated by the letters HW after the model number, e.g.: 909HW. The model M1 was introduced in 1989 in the 3/4"-2" and 4"-10" sizes. The 3/4"-2" size was changed by having the nipple between the body and the shutoff cast into the body instead of being a separate nipple. The repair parts on the 3/4"-2" 909 and 909M1 are the same. The 4"-6" size had a change on the relief valve body. The 909 design had a bronze relief valve body. In the 909M1 modification the relief body was changed to fused epoxy coated cast iron. The relief valve spring assembly was also changed. In the 8"-10" 909M1 sizes there was a change in the relief valve body. The relief valve utilizes the internal parts of the 4"-6" 909 unit. In the 909 M1 series the relief valve rubber repair parts will be the same in 4"-10". The check design will be similar to the 709. The check seats are replaceable and springs are contained when the covers are removed. The 2 1/2"-10" utilized an external relief valve sensing line and the relief valve body can be detached from the check body on these sizes. In 2010 a LF909 model was introduced in all sizes which replaced the internal leaded bronze parts with stainless steel and other lead free bronze materials. The rubber repair kit will fit both versions.


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.