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Topic: White pvc tank downstream of water pump (Read 438 times) previous topic - next topic

White pvc tank downstream of water pump

Can anyone suggest what this might be on my grand villa?
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: White pvc tank downstream of water pump

Reply #1 –
Looks like a small accumulator tank to smooth out the flow from the fresh water pump.  My 95 and 01 U320 have a 2 gallon tank.  I much prefer the tank to a multi-speed pump, by a bunch.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: White pvc tank downstream of water pump

Reply #2 –
Elliott,

And that is OEM from the factory. Yes FT tried to make their own in house surge tank back in that time frame of your coach build.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: White pvc tank downstream of water pump

Reply #3 –
Thanks guys. I don't understand how it works in this configuration with such a small line going into it but will keep it around
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: White pvc tank downstream of water pump

Reply #4 –
If you replace it with a real 2 gallon tank, you will be very pleased with the smooth flow of the fresh water.

The tank has a bladder inside that is pressurized to 25 or 30 psi with air.  The pump pushes water into the tank against that pressure which will partically fill the tank when the facuets are turned off.  When opening a facuet, the bladder pushes water into the system giving the pump time to respond to the flow of water.

The bigger tank does this better than a small tank.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: White pvc tank downstream of water pump

Reply #5 –
Homemade accumulator / surge tank, if it "waterlogs" (full of water and no air pocket) might as well not have it. it would be much better to have the small blue diaphragm or bladder tank. You may want to disconnect it to drain out any water that may be trapped i it.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: White pvc tank downstream of water pump

Reply #6 –
Quote from: FourTravelers –
Homemade accumulator / surge tank, if it "waterlogs" (full of water and no air pocket) might as well not have it.
You may want to disconnect it to drain out any water that may be trapped i it.
X2.  To operate that homemade pressure tank as intended, you should close the valve in the supply line, then open/remove the brass plug in the end opposite the inlet.  Drain out any water in the tank, then close/replace the plug.  Mount the tank vertically so the water inlet is on the bottom (facing down) and brass plug is on the top (looking up).  Then open the valve on the supply line.  You will need to drain the tank on a regular basis to prevent waterlogging.  See below:


1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: White pvc tank downstream of water pump

Reply #7 –
I have seen several of those that were broken because they had water in them and then the coach was subjected to freezing temperatures.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: White pvc tank downstream of water pump

Reply #8 –
Thanks guys - I suspected it was an accumulator but wasn't sure. It was installed horizontally on it's side and it'll have to remain that way if I want to keep it due to space constraints. If it doesn't work I'll have to consider upgrading the pump I suppose.
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: White pvc tank downstream of water pump

Reply #9 –
Quote from: Elliott –
Thanks guys - I suspected it was an accumulator but wasn't sure. It was installed horizontally on it's side and it'll have to remain that way if I want to keep it due to space constraints. If it doesn't work I'll have to consider upgrading the pump I suppose.

Unless it has a bladder inside, it's not going to do any good. I would remove it and give yourself some more room to put something else is the space.  If pipe was empty, once you turn pump on it is going to start filling with water on the bottom. When you turn a faucet on very little water, mostly air is going to be released until it is over half full of water. 
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: White pvc tank downstream of water pump

Reply #10 –

X2 what turbojack says - toss it in the trash.

Suggest you replace it with the one linked below, or something similar.  Can be connected inline to any cold water pipe (downstream of the pump) anywhere in the coach.  Works in any mounting position.  Will actually perform a useful function.  It should be installed in a place where you can get to the air valve to occasionally check the pre-charge.

Amazon.com: SHURflo 182-200 Pre-Pressurized Accumulator Tank,Black, 9.1" x...

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: White pvc tank downstream of water pump

Reply #11 –
Thanks guys - I'll look into replacing it with the accumulator chuck suggests. There's a whole mess of valves next to the pump that I need to retain access to as well and I'm still negotiating with the boss over what furniture is going to go over it.
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: White pvc tank downstream of water pump

Reply #12 –
 If you can fit a loop of water line, it will do the same thing as the little tank .  You just need a small air pocket to soften the pump pulses.
 Some place along the way I ran my system out of HOH and there must be an air pocket some where.  It works nice and keeps a little pressure on .   
 I also had the same tank as you showed. 

Re: White pvc tank downstream of water pump

Reply #13 –
The main drawback to depending on any sort of "small air pocket" -whether created accidentally or intentionally - is that the air is gradually absorbed by (dissolved into) the water, and the air pocket disappears.  Of course, you can always reestablish the air pocket, either manually or automatically, but why bother when there is a simpler way to accomplish the same end result.  Diaphragm and bladder pressure tanks were developed for this express purpose.  By keeping the air and water separated by an impermeable membrane, the pre-charged air pocket remains intact, and required maintenance is considerably reduced.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"