LPG Cylinder Swap

[rodwha]

I've seen how some LPG tanks/cylinders are measured by lbs and some by gals so I wondered if there was some sort of typo or maybe I just misunderstood as I thought all cylinders were measured by lbs so I looked at our outdoor grill and noticed a 15 lb cylinder and not a 20.

I have assumed these (BBQ grill) were standard size and that when it came time to swap cylinders for an RV you would do so at the grocery store. So where do you swap out 20 and 30 lb cylinders?

Also how does the weight to volume compare? How many gals does a 20 lb cylinder hold?

[tatest]

In most of the U.S. only the 20-pound cylinders are exchanged. Past few years, exchange cylinders have often been filled to less than 20 pounds, but at least now they are telling you that. Not too long ago they didn't.

You take larger cylinders to a LPG dealer for refills. In most states, they fill the cylinder on a scale and charge on the basis of weight added. Dealers in states where they are required to sell LPG by weight will do the same for 20-pounders, but often there will be a "minimum" charge not much different than the price of an exchange. Where they can't do this, there is sometimes resistance to refilling small cylinders, as the labor cost can exceed the margin on 10-20 pounds of LPG. (Labor cost vs margin on the sale is also why most of us are pumping our own gas and paying at the pump).

I do a lot of my LPG fills (permanently mounted tank) at RV parks rather than LPG dealers or second tier retailers. RV parks offering this service are doing it on a goodwill basis, rather than a profit center, with a small markup over what they pay for a refill. But because they pay retail, it might be a higher price per pound than buying from a wholesaler or first tier retailer.

As opposed to cylinders, which can be weighed, tanks have to be filled by liquid volume, metered at the pump, just like gasoline or diesel. In some states they may be allowed to price by gallon, in others they convert gallons to pounds and charge so much per pound.

[gotsmart]

I use 20 lb external tanks for my MH because of one thing - the Grill Gauge. linky. In the link, scroll down to the "Product Description" where it talks about why tank exchange companies choose to label their tanks as 15 lb tanks. The take-away for me is I'm beginning to take my Grill Gauge and weigh the tanks after I get them refilled. Why? A few of the stations that I use for propane write the info on a slip of paper that I take to the cashier to pay for the gas. There is a potential for dishonesty buy the merchant. When I am able to I also make a point to watch the gas meter says after the attendant finishes filling the tanks (or the MH's propane tank). I want to make sure that I get what I'm paying for.

[allen8106]

theoldwizard1 wrote:

rodwha wrote:
Reading a bit I see complaining about swapping and getting cheated, but then I also read the same of having them filled. Does anyone place a scale down at fillup?

My local propane filling station has a scale, but they don't use it 🙂 ! That is because they charge a flat rate to fill a 20# tank.

I am not an expert, but I have read that the proper way to fill a 20# tank is to attach the (liquid ?) hose and start the pump. Then open the bleeder valve (screwdriver required). When the bleeder starts to vent liquid (which immediately turns to gas when it hits the atmosphere), close the bleeder and turn off the pump.

Exactly correct.

[allen8106]

rodwha wrote:
Reading a bit I see complaining about swapping and getting cheated, but then I also read the same of having them filled. Does anyone place a scale down at fillup?

I wouldn't want to swap out new cylinders for an unknown one...

We have a propane business not far from us. I'd go there for now. I wondered about other times such as when you are out all summer, which we are looking forward to doing. The grocery store sure would be convenient... As an aside I'm wondering about filling our grill's cylinder there now that I'm thinking about it, rather than swapping it (15 lbs for about $15). I'll be sure to weigh it just to see from now on.

So I have my BBQ tanks and my 30lb RV tanks usually filled at 3 different places. One is a big city propane seller selling for industral forklifts, BBQ grills, campers, residential 300 gallons propane tanks and as several large delivery trucks. 2nd is a small town propane seller typiclly one delivery truck and filling the same BBQ and camper propane tanks. The third is a guy that has a 200 gallon tank in his yard and only fills BBQ tanks and camper tanks. I've watched them all fill my tanks and they all always one the bypass screw on the side of the tank valve and leave it open until propane starts spitting out. This allows the tank to fill as full as possible which is only 80% with todays OPD valve. I never exchange my BBQ tanks unless the pressure test date has expired and never ever exchange the RV tanks, one because I don't like to exchange and two theres no where to exchange the 30lb RV tanks.

[theoldwizard1]

3oaks wrote:
They charge the same price to top off a partially depleted tank as they do to refill a completely empty tank.

Same here, but the sign states that they do not weigh 20# tanks, so at least you know that going in. (I have always had a "spare" tank, even though my old pop up could only hold one.)

I am not sure what they would do for a smaller/larger tank.

[theoldwizard1]

rodwha wrote:
Reading a bit I see complaining about swapping and getting cheated, but then I also read the same of having them filled. Does anyone place a scale down at fillup?

My local propane filling station has a scale, but they don't use it 🙂 ! That is because they charge a flat rate to fill a 20# tank.

I am not an expert, but I have read that the proper way to fill a 20# tank is to attach the (liquid ?) hose and start the pump. Then open the bleeder valve (screwdriver required). When the bleeder starts to vent liquid (which immediately turns to gas when it hits the atmosphere), close the bleeder and turn off the pump.

[rodwha]

These cylinders, much like refrigerant for A/C that also expands when warmer, absolutely must be handled with a safety margin. No doubt this is why they are DOT approved. There's just no way they'd have a 20 lb cylinder that truly is maxed at that weight. If it weren't there'd be a lot of ruptured cylinders. A cylinder that is shorted is done so clearly for profit.

[Strabo]

It's all relative to what you expect. Camping using propane is not a big deal price wise or what difference the amount makes, in the sense of camping and it's expenses. I only get yelled at when we run out, because I thought what we had was enough and I pushed the envelope, so to speak.

See, camping is supposed to be fun. 🙂

[MitchF150]

I only exchange when my old cylinder is about to expire... I exchange a 12 year old cylinder for a new to at most a year old one for about $20.. Plus it has propane in it.. Go to the box store and a new cylinder costs $30+ and then you still have to fill it... No brainer to me...

Once I have the newer exchanged cylinder, I just get it refilled.. I see propane refill stations all over the place. Around here, it's all by the gallon.. I've filled empty ones that take around 4.5 gallons and some that I just want to top off and get 3 gallons.. Just get charged per gallon. Just like gas for the cars. Price varies from place to place, but seems to be a little less that gasoline per gallon for the most part.

Good luck!

Mitch

[vic46]

Last fill for my 20# BBQ tank was 11.73CAD. Filled by metre, only paid for what was put in the tank. The weight method is the same result, pay for what you get. If your tank is close to timeX, get an exchange tank and refill by metre or weight when it needs it.

Follow 2oldmen link - great information.

[Dutch_12078]

wanderingbob wrote:
It is not all cut and dried ! The capacity of a cylinder will vary with the temperature at the fill site . Can you imagine the problems with filling a semi-truck with cylinders in New Jersey winter and trucking them to South Florida . fifteen percent expansion is not uncommon . They are trucked all over the nation . Twenty percent of the interior must be left for expansion in swap situations .

Twenty percent is left for the liquid to boil off into a gas in all standard LP tanks and cylinders. The OPD (Overfill Prevention Device) will not allow it to be filled any more than that. Temperature variations will shrink or expand that space somewhat, but there's enough safety margin to accommodate that.

[wanderingbob]

It is not all cut and dried ! The capacity of a cylinder will vary with the temperature at the fill site . Can you imagine the problems with filling a semi-truck with cylinders in New Jersey winter and trucking them to South Florida . fifteen percent expansion is not uncommon . They are trucked all over the nation . Twenty percent of the interior must be left for expansion in swap situations .

[turbojimmy]

3oaks wrote:
Some people think exchange tanks are a rip off? Try my local propane supplier.
They charge the same price to top off a partially depleted tank as they do to refill a completely empty tank. I like to start a trip with two full propane tanks. However I always wait until I find a propane dealer that charges by the gallon to refill a partially used tank. Shop local.......not in my home area.

My local refiller keeps legitimately full 20# cylinders on-hand. So I'm exchanging, but for a full tank. $20 versus $30 at Lowe's for a 3/4 full tank.

[arhayes]

You're definitely better off getting your tank refilled somewhere that charges by the gallon. I have 2 30# tanks on the rig and also carry a 20# bottle for the grill. o always have enough propane on hand to be able to wait until I find the most economical way to refill them.