water expansion tank

[robymayway]

Hallo to all!
I have a little question about a problem of pressure in the water system.
Some days ago I have found a little wet area under the water expansion tank (4,75 gallons/ 18 litres ) and after a ready check I noticed that when galleymead pump run, there was a little leak of water.( there was an hole in the bottom side of tank ...age 29 years!!
So I have changed the tank giving precharged with air at 31 psi pressure.

I was hoping that everything was ok...but I have to desume there is a problem.

The problem is that galleymead pump works exactly for the time that I open the water tap and stop to work in the exact moment I close the tap.
When it is in stand by the manostat show 20psi and when it works, it show 17 psi.

One time, when I called water from the tap, it was necessary 8/10 seconds before the galleymead pump switch on, and when I closed the tap, the pump worked for 5/7 second before switched off.

What can be happened??
Also, when I have opened the tap for the first time after changing the tank , I have noticed that tank remained empty.
( I have done try the new tank before replacing it by my plumber, and it works correctly).

Could you help me?

roberto

 

[Boatsb]

The pressure in the tank may be too high. If it a tank for home water use it will have a higher pressure than on most of the boats.

 

[robymayway]

May be....I have just found a old thread that suggest to give pressure around 10 - 20 psi not more e not less.
???????

thanks Boatsb
RR

 

[captddis]

Bleed all the pressure off of the system then set the air press in the tank to about 20 psi and it should work properly.

 

[robymayway]

Bleed all the pressure off of the system then set the air press in the tank to about 20 psi and it should work properly.

Ok thanks I will try.
That sound good to find out the arrival the water into the tank, but what your opinion about the problem of reducing of pressure when pump is switch on?

 

[SKYCHENEY]

Tank pressure should be set the same as the cut-in pressure of your pressure switch. This is the same for home or boat. As stated, drain pressure down and add or release air to obtain proper pressure.

 

[Beckytek]

I don't have a Galley Maid pump but they all work the same. There should be an adjustment so you can set the turn-off pressure to 40 PSI. Your pump will pump until it reaches that point and shut off. It should not come on again until the pressure drops to 20 PSI. Make that adjustment and you should be good to go.

 

[robymayway]

The pressure in the tank may be too high. If it a tank for home water use it will have a higher pressure than on most of the boats.

yes! exactly, it is for home use. However I had already reduced the pressure at 31 psi from 60 psi.

I will do that.

 

[Nonchalant1]

If you fill with water before pressurizing, then you have too little air to work and you get the problem you described. Just turn off pumps, open water tap at a sink and let all pressure run out. Then turn off sink tap, pressurize tank with air to 20 PSI and turn on water pumps again. Water pressure will put water in the tank with more air than before.

 

[robymayway]

If you fill with water before pressurizing, then you have too little air to work and you get the problem you described. Just turn off pumps, open water tap at a sink and let all pressure run out. Then turn off sink tap, pressurize tank with air to 20 PSI and turn on water pumps again. Water pressure will put water in the tank with more air than before.

Thank you
I will do that tomorrow morning and I will let you know the result !!!
great help!

 

[robymayway]

Thanks to all!!!!!!!!
Lower pressurizing and eveything goes well again
This forum is really important! thankyou
roberto