Question:
I am working on a 2” Watts Model 909M1 assembly. The unit has failed the test and I want to replace the rubber parts. Can you tell me about this model and what to expect when I repair this unit?
Mark:
The Watts Model 909 began production in 1979. The smaller assemblies (¾-2”) utilize a bronze body and the repair procedures are the same for these sizes. In 1989, the 1 1/4”- 2” sizes were updated to a 909M1. The change was to the body of the assembly, so the internal components and repair procedures are exactly the same as the original version. A lead-free version, LF909, was introduced in 2010. No special tools are needed to change the rubber parts on this assembly. Each check valve cover is o-ring sealed and secured by four bolts. There is no spring load on the cover when removing the bolts. The 2” 909 is designed with a check assembly that is attached to the cover and the spring is contained. To remove, simply pull the cover and check straight out of the body without twisting. Turning the cover to the left or right will unload the spring prematurely.
Doug:
Once the access cover is off, the check valve components are exposed. The check valve is attached to the cover with a bayonet locking system. The check valve is spring loaded. To disassemble, carefully hold the cover and seat in both hands while pushing down and rotating the seat or (cage) ¼ turn. This will unlock the seat and the spring, freeing the disc holder. At this point, the white plastic seat or “cage” can be inspected for damage. The check valve disc is part of the brass disc holder and must be replaced as one piece. Reassemble the check valve in reverse order and make sure the seat o-ring is lubricated properly before reinstalling into the body.
Mark:
The relief valve is located underneath the assembly. The RV cover is sealed by the diaphragm and secured by six bolts. There is a slight spring load on the RV cover, so hold the cover as you remove the bolts. The sensing passage is located at the top of the cover and is a stainless tube that is o-ring sealed on both sides. The sensing line normally slides out with the cover. Once the cover is off, the RV stem assembly can be pulled straight out of the body. The RV seat is made of stainless steel and is threaded into the body and sealed by an o-ring. A special tool is required to remove the seat. Unless the seat is damaged, there is no need to remove it from the body.
Doug:
The diaphragm for the relief valve is located at the top of the RV stem. To remove, simply unscrew the stem cap from the stem. Once the stem cap is removed, the diaphragm and disc are free. The RV disc is an integral part of the disc holder, so they must be replaced as one piece. The RV stem also has o-rings that should be replaced. There is a small stem o-ring located on the stem that seals the RV disc holder. There is also a silicone piston o-ring located on the bottom of the stem near the spring. To reinstall the RV stem, insert the stem into the body. Carefully guide and depress the spring tension until the stem is completely into position. Insert a screwdriver up into the vent opening to hold the stem in place. Now the cover can be installed and bolted down easily. Be sure to remove the screwdriver from the vent once completed.
