Water Tank Overflow atten: you engineers

[jimlyndabrooks]

'Hello All,

This was discussed a few years ago, but no one had a solution.

Our fresh water tanks have a overflow pipe in the top front of the tank. When they were installed at the factory they drilled a small hole in the brass fitting to keep it from siphoning, but since the fitting only goes into the top of the tank, not into the water, I really do not understand the thinking.

Yes, I guess the fact that the top of the tank could flex downward and stay in contact with the water and cause a siphon, with the fitting in the extreme front corner, I do not buy the tank flex thinking.

I put a screw in the hole, to keep the lower compartment from getting wet when I filled the tank. This was 6 years ago.

Problem: When you stop the water in the tank surges forward and causes water to come out of the overflow which is a normal condition.

Ok you engineers: what would happen if you connected a tube/piping in a u shape going from the overflow pipe where it goes thru the floor to above the LP tank, thinking the column of water in the piping would provide weight against the water surge in the tank? The U shaped piping would be vented at the top of the loop and a small hole also in the bottom of the loop to allow it to drain so it would not hold water which could freeze in cold conditions.

It has been suggested a valve in the line, but you know at some point you would forget to open it and fill the tank with it closed.

Your thoughts?

Thanks Jim'

[stuplich@ymail.com]

'I don't think the hole IS an overflow.

I now believe that that hole is there to allow air to enter the water tank, so the water pump can draw water out, (worst case without: collapsed tank?).

Intake air may be the primary/only reason, with over flow into the bay a undesired side effect.

Six or eight years ago, I dropped the water tank, soldered the hole shut and added a second overflow, (using a tee, 1/2" plastic water pipe), with a shut off valve back at the water bay, (so I could easily tell when the tank got full), AND I used hose barb off the tee and a plastic hose to a type of standpipe, (similar to what a wash machine drain uses, but no P trap), drilled through the basement floor at the front, (just behind the bulkhead).

No more wet floor/carpet in the basement bay, but I still can loose as much as 1/3 of a tank if I travel any distance after a water fill.

At that time I had not even considered intake air, I just lucked out, (sometimes being anal has its advantages).

If I had not put the tee and front hose in, when I closed the valve on the back overflow I would have caused an air-lock! (I guess God truly does protect the ignorant).

Mel
'96 Sahara

--- In Safarifriends@yahoogroups.com, "jimlyndabrooks" wrote:
>
> Hello All,
>
> This was discussed a few years ago, but no one had a solution.
>
> Our fresh water tanks have a overflow pipe in the top front of the tank. When they were installed at the factory they drilled a small hole in the brass fitting to keep it from siphoning,

'

[jimlyndabrooks]

'Mel, I bought mine used, 6 years ago, the brass fitting on the top left corner of the fresh water tank had a hole, about 1/8" drilled in the top of it.

When I filled the tank, the water would come out both the 1/8" hole and out the 1/2" pipe that runs down the front bulkhead of the storage compartment to under it.

Since the tank can get air thru the overflow pipe, I sealed the 1/8" hole, thus fixing my wet compartment problem when I filled the tank. Now all the overflow water is directed to under the coach.

That same overflow pipe is where the water slosh comes out.

Trying to figure out a stupid proof way to stop the water loss when stopping, but retain the overflow/venting as required by the tank.

I blew the top out of a tank once, and was much younger then, so there is no way I am going to remember to do a valve thing 100% of the time. With a vertical loop filled with water, I am wondering if it would be enough to prevent slosh, but not over pressurize the tank when filled? Thinking the weight of the water would be enough to contain the force of the slosh.

The U shaped piping would have a venting hole (1/8-3/16") both at the top of the loop and one in the bottom to allow the loop to drain and not hold water causing a air lock like a P-trap does. Yes you would loose water out of the loop drain holes, but that would be much less than the loss now.

So, not knowing the psi the fresh water tank can take, not knowing for psi force of sloshed water, not knowing the weight of a column of water a couple feet tall in a 1/2" pipe, or the psi required to displace it, guess it is tinker time.

Jim
'96 Sahara 3540

--- In Safarifriends@yahoogroups.com, "stuplich@..." wrote:
>
> I don't think the hole IS an overflow.
>
> I now believe that that hole is there to allow air to enter the water tank, so the water pump can draw water out, (worst case without: collapsed tank?).
>
> Intake air may be the primary/only reason, with over flow into the bay a undesired side effect.
>
> Six or eight years ago, I dropped the water tank, soldered the hole shut and added a second overflow, (using a tee, 1/2" plastic water pipe), with a shut off valve back at the water bay, (so I could easily tell when the tank got full), AND I used hose barb off the tee and a plastic hose to a type of standpipe, (similar to what a wash machine drain uses, but no P trap), drilled through the basement floor at the front, (just behind the bulkhead).
>
> No more wet floor/carpet in the basement bay, but I still can loose as much as 1/3 of a tank if I travel any distance after a water fill.
>
> At that time I had not even considered intake air, I just lucked out, (sometimes being anal has its advantages).
>
> If I had not put the tee and front hose in, when I closed the valve on the back overflow I would have caused an air-lock! (I guess God truly does protect the ignorant).
>
> Mel
> '96 Sahara
>
> --- In Safarifriends@yahoogroups.com, "jimlyndabrooks" wrote:
> >
> > Hello All,
> >
> > This was discussed a few years ago, but no one had a solution.
> >
> > Our fresh water tanks have a overflow pipe in the top front of the tank. When they were installed at the factory they drilled a small hole in the brass fitting to keep it from siphoning,
>

'

[PETER GUZMAN]

'WOW what timing on this item.. I had just dumped all my fresh water and rinsed out my tank.. Filled it back up.
I noticed in the lower bay near the fresh water tank a puddle of water, fresh I tasted it.. (I hope).
So I cleaned it up and was puzzled and to where it originated. Hoping the reason for the puddle is the tank is 100% full. Fulltimers-Currently traveling around USA-In Durham, NC..
Regards,
Peter G....
08 Cheetah/Safari'

[stuplich@ymail.com]

'Jim

Mine did not originally have the 1/2" pipe but it did have the 1/8" hole, and ALL the slosh ended up in the bay carpet.

I thought perhaps a small check valve ,(like those used in home furnace/air cond), in that line might did the trick, (Air could come in but the water could not go out).

That would however require an overflow , (like mine in the water bay), which would HAVE to be opened when filling to prevent pressurizing the tank, (one more thing to remember).

What do you think?

Mel
'96 3530 Sahara

--- In Safarifriends@yahoogroups.com, "jimlyndabrooks" wrote:
>
> Mel, I bought mine used, 6 years ago, the brass fitting on the top left corner of the fresh water tank had a hole, about 1/8" drilled in the top of it.
>
> When I filled the tank, the water would come out both the 1/8" hole and out the 1/2" pipe that runs down the front bulkhead of the storage compartment to under it.
>
> Since the tank can get air thru the overflow pipe, I sealed the 1/8" hole, thus fixing my wet compartment problem when I filled the tank. Now all the overflow water is directed to under the coach.
>
> That same overflow pipe is where the water slosh comes out.
>
> Trying to figure out a stupid proof way to stop the water loss when stopping, but retain the overflow/venting as required by the tank.
>
> I blew the top out of a tank once, and was much younger then, so there is no way I am going to remember to do a valve thing 100% of the time. With a vertical loop filled with water, I am wondering if it would be enough to prevent slosh, but not over pressurize the tank when filled? Thinking the weight of the water would be enough to contain the force of the slosh.
>
> The U shaped piping would have a venting hole (1/8-3/16") both at the top of the loop and one in the bottom to allow the loop to drain and not hold water causing a air lock like a P-trap does. Yes you would loose water out of the loop drain holes, but that would be much less than the loss now.
>
> So, not knowing the psi the fresh water tank can take, not knowing for psi force of sloshed water, not knowing the weight of a column of water a couple feet tall in a 1/2" pipe, or the psi required to displace it, guess it is tinker time.
>
> Jim
> '96 Sahara 3540

'

[stuplich@ymail.com]

'Peter
I know this is not a site for "jokes", but your statement about tasting the water puddle caused this old one to pop into my head:

A camper was taking a walk and came upon a "present" that someone had neglected to pick up.

He said to himself,
"It looks like dog do"
"It smells like dog do"
"It TASTES like dog do"
"I sure am glad I didn't STEP IN IT"!

Everyone, please forgive me, I could not resist the temptation!

Mel

--- In Safarifriends@yahoogroups.com, PETER GUZMAN wrote:

> I noticed in the lower bay near the fresh water tank a puddle of water, fresh I tasted it.. (I hope).

> Peter G....
> 08 Cheetah/Safari
>

'

[whalberstadt]

'First of all, the "flex" thing is real. Here's what happens on my tank. I do not have the hole in the elbow filling. If I overfill my fresh water tank, flow starts coming out of the overflow tube, which terminates just below the bottom of the compartment where the tank is. I then shut off the water fill, and if I do nothing, the tank will continue to drain until about 20 to 25 gallons (of the 100 gallon tank) have drained, then the draining stops with an audible "whoosh" as air is sucked back up the drain tube.

When full, the tank walls bulge slightly. When the overflow starts, water fills the overflow tube. Since the bottom of the tube is significantly lower than the highest point of the water, a siphon is established. The siphon will continue until air can somehow get into the tank. Until then, the siphon will continue to "pull" water out of the tank as the tank walls flex back inward. If the distance from the top of the tank to the outlet of the drain tube is 55 inches, the siphon will pull with a suction of 2 psi. Until the resistance of the tank walls to flexing exerts enough force to overcome this 2 psi suction, the draining will continue. When the walls do finally exert that much force, air will be sucked back up the drain tube, the draining stops, the walls flex back out, and you could then finally see a water level (water/air interface) in the tank.

In my case, I have a three way valve on the pump suction line which I use to let the pump suck in antifreeze or Clorox solution, via an attached vinyl tube. Whenevr I am dumb enough to overfill the tank, I can open the valve and blow into the vinyl tube to force air into the tank, which breaks the siphon.

That's why you have a hole in the elbow at the top of the drain tube. If your "slosh" draining problem occurs only with a full tank, the above mentioned siphoning could be most of the problem.

I'm not sure whether your proposed "U" will help with the "slosh" draining problem. I would think the slosh would still happen and send water to the U, which would then drain via the hole you mentioned. there will be no column of water normally in the U, since you said you would put a drain hole at the bottom.

Bill Halberstadt

--- In Safarifriends@yahoogroups.com, "jimlyndabrooks" wrote:
>
> Hello All,
>
> This was discussed a few years ago, but no one had a solution.
>
> Our fresh water tanks have a overflow pipe in the top front of the tank. When they were installed at the factory they drilled a small hole in the brass fitting to keep it from siphoning, but since the fitting only goes into the top of the tank, not into the water, I really do not understand the thinking.
>
> Yes, I guess the fact that the top of the tank could flex downward and stay in contact with the water and cause a siphon, with the fitting in the extreme front corner, I do not buy the tank flex thinking.
>
> I put a screw in the hole, to keep the lower compartment from getting wet when I filled the tank. This was 6 years ago.
>
> Problem: When you stop the water in the tank surges forward and causes water to come out of the overflow which is a normal condition.
>
> Ok you engineers: what would happen if you connected a tube/piping in a u shape going from the overflow pipe where it goes thru the floor to above the LP tank, thinking the column of water in the piping would provide weight against the water surge in the tank? The U shaped piping would be vented at the top of the loop and a small hole also in the bottom of the loop to allow it to drain so it would not hold water which could freeze in cold conditions.
>
> It has been suggested a valve in the line, but you know at some point you would forget to open it and fill the tank with it closed.
>
> Your thoughts?
>
> Thanks Jim
>

'

[whalberstadt]

'Air can enter the tank under normal use via the overflow tube, so that's not why the hole is in the elbow. It's there to prevent siphoning when the tank is overfilled and the overflow tube would be full of water.

Bill Halberstadt

--- In Safarifriends@yahoogroups.com, "stuplich@..." wrote:
>
> I don't think the hole IS an overflow.
>
> I now believe that that hole is there to allow air to enter the water tank, so the water pump can draw water out, (worst case without: collapsed tank?).
>
> Intake air may be the primary/only reason, with over flow into the bay a undesired side effect.
>
> Six or eight years ago, I dropped the water tank, soldered the hole shut and added a second overflow, (using a tee, 1/2" plastic water pipe), with a shut off valve back at the water bay, (so I could easily tell when the tank got full), AND I used hose barb off the tee and a plastic hose to a type of standpipe, (similar to what a wash machine drain uses, but no P trap), drilled through the basement floor at the front, (just behind the bulkhead).
>
> No more wet floor/carpet in the basement bay, but I still can loose as much as 1/3 of a tank if I travel any distance after a water fill.
>
> At that time I had not even considered intake air, I just lucked out, (sometimes being anal has its advantages).
>
> If I had not put the tee and front hose in, when I closed the valve on the back overflow I would have caused an air-lock! (I guess God truly does protect the ignorant).
>
> Mel
> '96 Sahara
>
> --- In Safarifriends@yahoogroups.com, "jimlyndabrooks" wrote:
> >
> > Hello All,
> >
> > This was discussed a few years ago, but no one had a solution.
> >
> > Our fresh water tanks have a overflow pipe in the top front of the tank. When they were installed at the factory they drilled a small hole in the brass fitting to keep it from siphoning,
>

'

[David Coy]

'Why not run the overflow line over to the fill area and add a valve at the end,mark it open while filling and close when full.You have to open and close the fill valve,this eill remind you to open and close the vent valve especially when it comes squirting out when full! put a screw in the hole with some silicone on it and no more slosh and no more siphon. Dave in Hillsboro ohio 2000 Panther 425  (for sale) 937 763 0164

--- On Sun, 11/20/11, stuplich@... wrote:

From: stuplich@...
Subject: [Safarifriends] Re: Water Tank Overflow atten: you engineers
To: Safarifriends@yahoogroups.com
Date: Sunday, November 20, 2011, 11:03 AM

  Jim

Mine did not originally have the 1/2" pipe but it did have the 1/8" hole, and ALL the slosh ended up in the bay carpet.

I thought perhaps a small check valve ,(like those used in home furnace/air cond), in that line might did the trick, (Air could come in but the water could not go out).

That would however require an overflow , (like mine in the water bay), which would HAVE to be opened when filling to prevent pressurizing the tank, (one more thing to remember).

What do you think?

Mel
'96 3530 Sahara

--- In Safarifriends@yahoogroups.com, "jimlyndabrooks" wrote:
>
> Mel, I bought mine used, 6 years ago, the brass fitting on the top left corner of the fresh water tank had a hole, about 1/8" drilled in the top of it.
>
> When I filled the tank, the water would come out both the 1/8" hole and out the 1/2" pipe that runs down the front bulkhead of the storage compartment to under it.
>
> Since the tank can get air thru the overflow pipe, I sealed the 1/8" hole, thus fixing my wet compartment problem when I filled the tank. Now all the overflow water is directed to under the coach.
>
> That same overflow pipe is where the water slosh comes out.
>
> Trying to figure out a stupid proof way to stop the water loss when stopping, but retain the overflow/venting as required by the tank.
>
> I blew the top out of a tank once, and was much younger then, so there is no way I am going to remember to do a valve thing 100% of the time. With a vertical loop filled with water, I am wondering if it would be enough to prevent slosh, but not over pressurize the tank when filled? Thinking the weight of the water would be enough to contain the force of the slosh.
>
> The U shaped piping would have a venting hole (1/8-3/16") both at the top of the loop and one in the bottom to allow the loop to drain and not hold water causing a air lock like a P-trap does. Yes you would loose water out of the loop drain holes, but that would be much less than the loss now.
>
> So, not knowing the psi the fresh water tank can take, not knowing for psi force of sloshed water, not knowing the weight of a column of water a couple feet tall in a 1/2" pipe, or the psi required to displace it, guess it is tinker time.
>
> Jim
> '96 Sahara 3540

'

[David Coy]

'P.S. A check valve added by inserting a T in the line would let air in to the tank when needed and close when water tried to come out Dave

--- On Sun, 11/20/11, David Coy wrote:

From: David Coy
Subject: Re: [Safarifriends] Re: Water Tank Overflow atten: you engineers
To: Safarifriends@yahoogroups.com
Date: Sunday, November 20, 2011, 3:46 PM

  Why not run the overflow line over to the fill area and add a valve at the end,mark it open while filling and close when full.You have to open and close the fill valve,this eill remind you to open and close the vent valve especially when it comes squirting out when full! put a screw in the hole with some silicone on it and no more slosh and no more siphon. Dave in Hillsboro ohio 2000 Panther 425  (for sale) 937 763 0164

--- On Sun, 11/20/11, stuplich@... wrote:

From: stuplich@...
Subject: [Safarifriends] Re: Water Tank Overflow atten: you engineers
To: Safarifriends@yahoogroups.com
Date: Sunday, November 20, 2011, 11:03 AM

  Jim

Mine did not originally have the 1/2" pipe but it did have the 1/8" hole, and ALL the slosh ended up in the bay carpet.

I thought perhaps a small check valve ,(like those used in home furnace/air cond), in that line might did the trick, (Air could come in but the water could not go out).

That would however require an overflow , (like mine in the water bay), which would HAVE to be opened when filling to prevent pressurizing the tank, (one more thing to remember).

What do you think?

Mel
'96 3530 Sahara

--- In Safarifriends@yahoogroups.com, "jimlyndabrooks" wrote:
>
> Mel, I bought mine used, 6 years ago, the brass fitting on the top left corner of the fresh water tank had a hole, about 1/8" drilled in the top of it.
>
> When I filled the tank, the water would come out both the 1/8" hole and out the 1/2" pipe that runs down the front bulkhead of the storage compartment to under it.
>
> Since the tank can get air thru the overflow pipe, I sealed the 1/8" hole, thus fixing my wet compartment problem when I filled the tank. Now all the overflow water is directed to under the coach.
>
> That same overflow pipe is where the water slosh comes out.
>
> Trying to figure out a stupid proof way to stop the water loss when stopping, but retain the overflow/venting as required by the tank.
>
> I blew the top out of a tank once, and was much younger then, so there is no way I am going to remember to do a valve thing 100% of the time. With a vertical loop filled with water, I am wondering if it would be enough to prevent slosh, but not over pressurize the tank when filled? Thinking the weight of the water would be enough to contain the force of the slosh.
>
> The U shaped piping would have a venting hole (1/8-3/16") both at the top of the loop and one in the bottom to allow the loop to drain and not hold water causing a air lock like a P-trap does. Yes you would loose water out of the loop drain holes, but that would be much less than the loss now.
>
> So, not knowing the psi the fresh water tank can take, not knowing for psi force of sloshed water, not knowing the weight of a column of water a couple feet tall in a 1/2" pipe, or the psi required to displace it, guess it is tinker time.
>
> Jim
> '96 Sahara 3540

'