SHURflo reports this is a direct screw-in replacement for SHURflo pumps used by Catalina beginning in July 2008. SHURflo also reports it also has the same mounting hole pattern as the pumps used from 1988 until 2008. There is no record of the mounting hole pattern of earlier pumps. New mounting holes may have to be drilled into the plywood mounting platform on boats built prior to 1988, but this is a very simple procedure. Our pump includes hose barb adapters for the 1/2" ID hose used in most Catalinas.
The three chamber diaphragm design is just one of many pump models offered by SHRUflo. This type of pump, regardless of manufacturer, is designed to be used in conjunction with an accumulator tank.
An accumulator tank provides a volume of space filled with air that can be compressed by the pressure pump. A bladder in the accumulator separates the water from the air. Since air can be compressed to a greater degree than water, the accumulator smoothes out the flow of water from the pump which is either on or off. It also keeps the pump from cycling on and off so frequently.
Unfortunately, due to both cost and space constraints, Catalina Yachts uses accumulator tanks only in their largest boats. As a result, the pressure pump will cycle on and off frequently. Luckily, the multi-chamber design has smoother operation than the earlier single diaphragm pumps used for decades by many builders.
Most modern pumps, this one included, are built with 1/2" pipe threads on the inlet and outlet. Our pump includes two fittings to adapt the 1/2" pipe thread to 1/2" hose barbs. Most Catalinas require the hose barb adapters.
Note: This pump is suitable for use in any Catalina originally equipped with pressure water from the factory. It may also be used to retrofit any early boat (like a Catalina 27) originally equipped with manual pumps. Our research indicates Catalina Yachts purchased these pumps during the periods mentioned above. There is no guarantee that every boat built used the same pump. If their vendor ran out of pumps, Catalina didn't stop building boats! They may have purchased another substitute pump in order to continue production until their regular pump vendor was able to resupply them. In any case, this pump will work well.