propane tanks on manifold question

[FMC]

2 100 lb propane cylinders on T with separate gas valves to intake of regulator (single port)
question is .. will the 2 tanks equalize their volume, ie. are the bottle valves one way? I would like to start system with 1 full and one 50% so they can be swapped without total shut down of unit. Is a one way valve available or not necessary. Thanks

 

[Rogue1987]

Yes I think you'd need a check valve on one of the lines to keep the amount of propane in both tanks from equalizing. But if you've got valves on the tanks to facilitate swapping the tank while ones still in service, couldn't you just leave one tank valve closed until you get low on the other? Assuming you have a way to gauge the amount of remaining fuel (wiggle the tank?)

Sent from my SM-G900V using Tapatalk

 

[FMC]

Thanks Rogue, certainly could do that but would be better if tank ran dry as costco dosent charge by weight

 

[Randy in Maine]

My 2 x 100 gallon tanks are set up to equalize, but my guy fills them both up at the same time. I don't want to re-light all of the stuff when one tank runs out.

Just put a shut off on both sides of the T then you can run one until it is empty and then switch to the other one.

 

[BD1]

Why not install a independent positive shutoff valve on each ?

 

[FMC]

thanks guys, each tank has its own shutoff valve, just needed to know if one tank would empty, seems it will so ill have to find some check valves.

 

[yeldogt]

Mine are piped together. Don't you have a valve at the top of each tank?

I can shut one off and draw down either tank if I want. When they are both filled I shut one off -- that way if I have a leak or something malfunctions I don't loose both full tanks.

 

[gungatim]

on my travel trailer, 2x30 tanks to single regulator, if I leave both open they will equalize, so we always keep one off til the other is empty. once made the mistake of leaving one open while other tank was off getting filled and had a leak through the disconnected hose...won't make that mistake again...I assume the same setup with your 100 gallons, keep one shut off until the other empties, assuming you don't need the dual capacity to feed some gas hungry appliance...

 

[FMC]

yeldogt,yes, both tank valve and gas **** for each line, ty.
gungatim thanks, gas hungry mmm think so its a 100k pool heater, (pool is in the garage so i dare not mention that lol)

 

[yeldogt]

yeldogt,yes, both tank valve and gas **** for each line, ty.
gungatim thanks, gas hungry mmm think so its a 100k pool heater, (pool is in the garage so i dare not mention that lol)

Pool on propane Mine is 400k .. but NG.

They will = out if both valves open

 

[FMC]

thanks yeldogt, guess ill put tanks on weight scales and wing it lol, 400k must be a beast, im hoping indoors wont be too ugly or wife will be getting a drysuit

 

[Bondo]

thanks yeldogt, guess ill put tanks on weight scales and wing it lol, 400k must be a beast, im hoping indoors wont be too ugly or wife will be getting a drysuit

Ayuh,.... They make a tandem regulator that would take the place of yer T fittin',....

I've got one on my house, with 2, 100 lb. tanks,....
It's got alittle flip switch that points to the tank used last,....
It switches to the full tank, when one runs out,....

There's a pop-up gauge that tells ya whether it's switched tanks or not,...

If it's red, ya change the empty, 'n flip the switch over,...

 

[FMC]

hi bondo, i looked at those regs and one side is primary full draw and the other side is reserve with less draw, might be other ones not like that but this one was in stock and i passed it by

 

[dfiler2]

http://www.amazon.com/dp/B005F33270/?tag=atomicindus08-20

 

[FMC]

thanks dfiler, same thing the primary side is higher than the reserve side

 

[404]

Thanks Rogue, certainly could do that but would be better if tank ran dry as costco dosent charge by weight

Where is there a costco that fills a 100 lb tank?

 

[FMC]

404? canaduh, we haz gasssses

 

[CNGsaves]

^ ^ ^ Good point . . . . Canada is swimming with oil & gas resources.

Let's hear PRICE that you Canucks pay per US gallon for LPG/Propane ???

 

[FMC]

costco 20lb propane was 12.95, been down for a while, so warm this winter im up a pile of dough haha

 

[A_Pmech]

The draw from each cylinder will be roughly equal, but they will not equalize in volume of fuel contained. For that to happen, gas boiled off one volume must pass through the manifold and condense in the other volume.

 

[joe_padavano]

Every RV with dual propane tanks has an automatic switchover valve. One tank drains, and when pressure in that tank drops, the valve automatically switches to the other. The valve also has a flag that lets you know when the first tank is empty.

 

[404]

The draw from each cylinder will be roughly equal, but they will not equalize in volume of fuel contained. For that to happen, gas boiled off one volume must pass through the manifold and condense in the other volume.

Exactly, thank you.

 

[FMC]

thanks joe

Every RV with dual propane tanks has an automatic switchover valve. One tank drains, and when pressure in that tank drops, the valve automatically switches to the other. The valve also has a flag that lets you know when the first tank is empty.

The draw from each cylinder will be roughly equal, but they will not equalize in volume of fuel contained. For that to happen, gas boiled off one volume must pass through the manifold and condense in the other volume.

Right up until first cylinder is empty then what?

The switching regulators seem to have a primary side full draw and a reserve side with lower draw, cannot find explanation on how exactly that works or the implications for appliance operation.

 

[Bondo]

thanks joe




Right up until first cylinder is empty then what?

The switching regulators seem to have a primary side full draw and a reserve side with lower draw, cannot find explanation on how exactly that works or the implications for appliance operation.

Ayuh,.... Best I can tell ya is, mine draws off the tank the little paddle switch arrow is pointed at, til it can't supply the pressure/ volume to the regulator,...
At that point, the red indicator pops up, 'n it switches, automatically to the 2nd tank,....

I go out, 'n turn off the empty tank, flip the little paddle switch to point at the full tank, unscrew the empty tank, pull it, slide in another full tank, screw in the connector, note the date under the hood, 'n close the hood,...

I'll get the empty tank filled, 'n leave it sittin' next to the hooked up tanks for a year or so, 'n then do it all over again,...

'n it can All be done while a turkey is in the oven, a load of clothes in the dryer, 'n usin' the hot water in the summer time,...

 

[joe_padavano]

thanks joe

The switching regulators seem to have a primary side full draw and a reserve side with lower draw, cannot find explanation on how exactly that works or the implications for appliance operation.

I've been using one with a pair of 100 lb tanks for over a decade. There is no effect on appliance operation. You never even know the valve switches until you check it (or the second tank also runs out... ). By the way, the one I have does not have a primary and backup side. Both sides work exactly the same.

 

[TractorJeff]

See #12, #21, #24 and #25! this is the way all the ones I have ever seen work! they are equal draws. Guy comes and swaps one tank at a time. Houses are heated, clothes dried, food cooked!

 

[FMC]

thanks all for the replies, TractorJeff, I might contact the mfg about clarification of the lower draw side as no one seems to know. cheers

 

[Bondo]

thanks all for the replies, TractorJeff, I might contact the mfg about clarification of the lower draw side as no one seems to know. cheers

Ayuh,.... What are you callin' the Lower draw Side,..??

 

[yeldogt]

I just read your post again -- do you have 100 gallons or pounds?

Mine are 100 gallons -- so no switching those. They come and fill them up.

And mine only have one regulator after both tanks. If I open the valve between both tanks -- the filled tank will absolutely start to fill the other (empty) tank.


If you only have 100 lb's how long will that run a pool heater?

 

[FMC]

Ayuh,.... What are you callin' the Lower draw Side,..??

finally found an answer

"

The MEGR-9984 by Marshall Excelsior automatically redirects LP gas flow from an empty designated service cylinder to a reserve cylinder, without interruption of service. It features a green indicator dome which changes to red when the service cylinder needs to be refilled.
Zinc die cast
Molded rubber diaphragms
UL listed
2nd stage relief mechanism per U.L. 144
1/4" female flare inlet x 3/8" FPT outlet
Service cylinder 500,000 BTU/Hr
Reserve cylinder 200,000 BTU/Hr"

this is the first site that shows actual numbers for the lower reserve side, it would be fine for me.

 

[FMC]

I just read your post again -- do you have 100 gallons or pounds?

Mine are 100 gallons -- so no switching those. They come and fill them up.

And mine only have one regulator after both tanks. If I open the valve between both tanks -- the filled tank will absolutely start to fill the other (empty) tank.


If you only have 100 lb's how long will that run a pool heater?

tanks should run 24 hrs on high
they are 100 lb tanks, initial heat up will use a couple but pool is inside the garage, insulated and covered, maintaining heat time will tell. Thanks