Conbraco 40-200 (RP40): How To Repair
I need to repair a 2” Conbraco 40-200. Can you guys give me a little overview of this device so that I’ll know what to expect when I arrive? Also let me know if I’ll need any special tools for disassembly.
The Conbraco 40-200 (AKA RP40) started production in 1989 and was discontinued in 2014. It is a reduced pressure principle assembly and is offered in ¼ – 2” sizes. Early models of the Conbraco 40-200 or RP40 series did not always have replaceable check seats. In 1994 replaceable seats became standard. To remove the seats, a special tool is required. This model uses poppet style check valves with a top entry design. Now we will go through the repair procedures.
Let’s get started with the check valves. The check covers are threaded into the body and sealed with an o-ring. Using an adjustable wrench, loosen the cover by turning counter-clockwise.
The check valve springs are not contained so there is a spring load on the covers. The spring and poppet are free once the cover has been removed. The check valve disc is accessible by removing the retaining screw and washer from the plastic poppet.
The check valve seats are sealed by an o-ring and threaded into the body. A special tool is needed to remove the check seats.
After servicing the check valves, we can turn our attention to the relief valve. The relief valve is located on the bottom of the assembly. The relief valve cover is sealed by the diaphragm and has a slight spring load. Once the cover bolts are removed, the diaphragm and cover are free.
The RV assembly is o-ring sealed and can be pulled straight out of the body. The RV seat is threaded into the body and sealed by an o-ring. A special tool will be needed if the RV seat needs to be replaced.
To replace the RV disc, simply remove the retaining screw and washer from the front of the stem.
The relief valve assembly is spring loaded and must be disassembled to replace the stem o-ring. To do this, hold the stainless diaphragm plate firmly and remove the retaining screw.
Once the retaining screw is removed, the spring, stem and bushing are free.
The stem o-ring should be replaced and lubricant applied. Reassemble the RV assembly in reverse order.