Boom goes my fresh water tank....

[Halmfamily]

Leaving on Wednesday for a five day trip, filled fresh water tank half full per tank indicator so we can start preparing and boom the water tanks holding brackets bent and the tank fell out. Wow that was a loud noise, shook the fiver and my son heard it from inside the house.

Pulled back the coroplast and both the fore and aft L brackets were bent downwards. I drained the tank and put a ratchet strap under it to keep it in place. Forest River will get a call first thing in the morning to see what they can do, still under warranty. if push comes to shove I'll remove the aft bracket and remove tank so we can still take our trip.

I'm just glad this didn't happen while pulling it down the interstate. Sorry,, just had to vent. I'd post pictures but only have a tablet.

Happy Fourth everyone.

[laknox]

Halmfamily wrote:
Op here. I finally figured out what to name our fiver, FUBAR. Thanks for the idea. :B

:B:M:B:M:B...

Lyle

[CJW8]

Halmfamily wrote:
Op here. I finally figured out what to name our fiver, FUBAR. Thanks for the idea. :B

:B:o

[Halmfamily]

Op here. I finally figured out what to name our fiver, FUBAR. Thanks for the idea. :B

[laknox]

CJW8 wrote:
Call it what you like, FUBAR fits pretty good.

:B

Lyle

[2_many_2]

CJW8 wrote:
Call it what you like, FUBAR fits pretty good.

:B:E

[CJW8]

Call it what you like, FUBAR fits pretty good.

[laknox]

CJW8 wrote:
Well my vent line is a 3/8" hose. My fill hose was 5/8" water hose with good pressure. I got distracted while filling and when I caught it, water was spraying out the vent line about 30 feet and also leaking a lot around the fill point. I had two tanks. Top was an 80 gallon tank in the pass through storage area. It was translucent plastic rectangular shaped and it looked like a basketball. I didn't look at the belly tank but it was significantly bowed out on the bottom to bend 2ea. 1 1/2" angle iron pieces.

So if the vent and the small area around the fill hose are not keeping up with the water going in, the tanks will pressure up very quickly.

A typical 40 gallon RV FW tank is 42" 26.75" 9.5" . That is 1123.5 square inches of surface area on the top and the same on the bottom of the tank. If the pressure inside the tank was only up to 0.5 PSI (pounds per square inch) then that is a force of 561.75 pounds on the top of the tank. It is also 561.75 plus the static head of 9.5 inches of water column (height of tank) = .34 PSI for a total of .84 PSI on the bottom, so it is also 943.74 pounds of force on the bottom of the tank, 127.0625 pounds of force on both ends of the tank and 199.5 pounds of force on both sides of the tank.

So yes, it is designed to carry it's rated capacity 332 pounds of total weight but it is not designed for the kinds of forces above. The forces above cause tanks to bend/break supports, burst etc.

OK, I'll agree with you that this can FUBAR a tank pretty good, though I'd call it an "overpressure" rather than an "overfill". 🙂

Lyle

[CJW8]

Well my vent line is a 3/8" hose. My fill hose was 5/8" water hose with good pressure. I got distracted while filling and when I caught it, water was spraying out the vent line about 30 feet and also leaking a lot around the fill point. I had two tanks. Top was an 80 gallon tank in the pass through storage area. It was translucent plastic rectangular shaped and it looked like a basketball. I didn't look at the belly tank but it was significantly bowed out on the bottom to bend 2ea. 1 1/2" angle iron pieces.

So if the vent and the small area around the fill hose are not keeping up with the water going in, the tanks will pressure up very quickly.

A typical 40 gallon RV FW tank is 42" 26.75" 9.5" . That is 1123.5 square inches of surface area on the top and the same on the bottom of the tank. If the pressure inside the tank was only up to 0.5 PSI (pounds per square inch) then that is a force of 561.75 pounds on the top of the tank. It is also 561.75 plus the static head of 9.5 inches of water column (height of tank) = .34 PSI for a total of .84 PSI on the bottom, so it is also 943.74 pounds of force on the bottom of the tank, 127.0625 pounds of force on both ends of the tank and 199.5 pounds of force on both sides of the tank.

So yes, it is designed to carry it's rated capacity 332 pounds of total weight but it is not designed for the kinds of forces above. The forces above cause tanks to bend/break supports, burst etc.

[laknox]

CJW8 wrote:
I think a lot of people over fill their tanks at some point or another and end up damaging the supports. Don't ask me how I know. My Forest River had flat edges in the tank that ran the fill width of the frame that supported the tank. (angle iron on top of the frame) It also had two pieces of angle iron under the tank. These were on edge like an inverted "V" and welded to the top edge of the lower part of the I beam. These bent when I over filled the tank. I used jacks to put them back in place.

How can you "overfill" your tank? I've never seen a fresh tank that won't overflow out the vent when it's full. It's either designed to be able to carry it's rated capacity while sitting still or under way, or it's a shoddy design (or build)...PERIOD. That extra 1-2 gallons, if that, that's in the vent and fill lines isn't going to "overfill" your tank.

Lyle

[Halmfamily]

tinner12002 wrote:

24fb freedom wrote:

heres what mine came with from the factory, lol
Each 100 gal tank had only three 1 1/2" angle iron supporting the sag of the tank.

I rest my case!

Op here, mine was similar to the picture but screwed into the side of the frame. 1/2" L brackets on front and back and three thin metal bottom supports is all that held it in. The bottom supports were only welded onto one L bracket and not the other side. Talked with my dealer again and they are going to add supports at the top and use straps, like on a fuel tank, to support the tank. Said it will not move when they're done.

[Stefonius]

All of this is scary. Now I'm going to have to drop the coroplast from my underbelly and spend time staring up at the guts of my coach. Thanks a lot!

[tsetsaf]

Not uncommon for FR... I know of two others that did the same.

[CJW8]

I think a lot of people over fill their tanks at some point or another and end up damaging the supports. Don't ask me how I know. My Forest River had flat edges in the tank that ran the fill width of the frame that supported the tank. (angle iron on top of the frame) It also had two pieces of angle iron under the tank. These were on edge like an inverted "V" and welded to the top edge of the lower part of the I beam. These bent when I over filled the tank. I used jacks to put them back in place.

[tinner12002]

24fb freedom wrote:

heres what mine came with from the factory, lol
Each 100 gal tank had only three 1 1/2" angle iron supporting the sag of the tank.

I rest my case!