In a fresh water system without a pressure tank the water pump will start immediately when a tap is opened and stop immediately after, however if you only open the tap partially it will cycle on / off continuously trying to maintain the correct pressure. If a pressure tank is added the cycling of the pump will reduce dramatically and smaller amounts of water can be released without the pump even starting.
We selected the Groco Pressure Tank PST-2 which is a very reasonable size for our 37 foot sailing yacht. The PST-2 holds 1.4 gallons which should be reasonable for a smaller fresh water system.
The tank comes with 3/4″ thread connection, and in our case we need to connect to a 1/2 inch hose so a few adapters were needed as can be seen in the image below. Be sure to use plenty of teflon tape in the connections to ensure a leak-free connection, I failed on this in the first attempt and had to redo it.
Once the hose adapter is in place its time to mount the tank, its held in place with two large hose clamps that’s attached to two stainless steel mount feet on each side of the tank, easy and simple installation. Make sure to follow the instructions on the correct location of the mount feet so the tank will be fitted firmly. The tank can be mounted either horizontally or vertically. In this installation it was best suited horizontally.
Once in place and secured its time to connect it to the water system, we used a T-connection to connect it to the fresh water flow from the pump.
Once connected it is time to turn on the water and check for leaks, as mentioned earler I did encounter leaks at the stainless steel couplings which was resolved by adding more teflon between the treads. Once leaks are rectified its time to check the pressure.
The tank pressure should be 2 psi less than your pump cut-in pressure. In our case we had a SHURflo 2901-0216 which per specification has a cut-in pressure of 25 psi, which means the tank pressure should be about 23 psi. Unfortunately I did not have a gage available at time of installation, so had to rely on a test.
Without adjusting the pressure of the groco tank I noticed no difference in the pump cycling, however after releasing some air by pressing the release valve on the tank, the system started working, I could hear the pump running and filling up the tank with water. After releasing a bit more it started to operate smoothly. I will update the post once I have verified the pressure and if I made any further adjustments.
Installation completed, drop a comment below if you have any questions or would like to know more!