Thread Tools Display Modes
Old 11-23-2013, 05:15 PM   #1
Senior Member
Hallen01's Avatar
Join Date: Dec 2010
Posts: 102
SSmall (1-gal) Tank for Portable Gas Grill

The "1-gallon" tanks for, say a Weber Q-Grill, with a hose to connect them are a worthwhile investment, over the hassle and expense of buying 1-lb "green" bottles of propane.

I'm too embarrassed to admit why I had to figure this out, but I thought I had a tank with a defective overfill protection device (OPD), until by chance I got a tech to fill the tank who was a certified fill technician instructor.

First, the density of propane is 4.4 lbs/gal, and that of water is 8.32 lbs/gal.

Second the stamping on the cylinder "TW 11 lbs" means tare weight (actually 11.1 by digital scale).

Thirdly, the stamping on the cylinder "WC 12 lbs" means water capacity (lbs), NOT weight capacity of propane

Fourth, a cylinder or tank (the latter, found in motorhomes, is not DOT regulated) may not be filled in excess of 80 percent. On a motorhome propane tank, the 100% mark on the gauge is at 80% of the capacity as stated on the manufacturer's label welded to the tank.

So, the tech checks a chart for fill volume, or you can make the calculation:

12 lb water capacity x 4.4/8.32 x 0.80 = 5.0 lbs

So the gross weight of a full (80%) cylinder is ~16.1 lbs.

Guess what: If you can't get anymore propane in a tank that weighs about 16 lbs, the OPD is not stuck; it's just full

Hallen01 is offline   Reply With Quote
Old 11-23-2013, 05:48 PM   #2
Senior Member
Ford Idaho's Avatar
Join Date: Sep 2013
Location: Idaho
Posts: 9,037
Thanks for the information.

I have a spare 20# tank from an older grill, that will feed my Coleman grill, two burner stove and lantern for some time via a
Coleman distribution tree.

2016 F350 6.7L LB CC Reese 28K 2014 Chaparral Lite 266sab
"Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety." 2014 19 days camping 2015 17 days camping201620 days camping
Ford Idaho is offline   Reply With Quote
Old 11-23-2013, 05:49 PM   #3
Senior Member
Join Date: Nov 2012
Location: X
Posts: 2,781
I'm sorry my friend, but this just isn't true. It's a story told by the tank exchange companies.

A 20# bottle will hold 20 pounds of propane when it's been filled to the max of 80% full.

Here's a few references. You can find many more on Google.
BarryD0706 is offline   Reply With Quote
Old 11-23-2013, 08:44 PM   #4
Phat Phrog Stunt Team
TURBS's Avatar
Join Date: Aug 2011
Location: Iowa
Posts: 34,205
I bought a schnozzle and just refill my 1# "green" tanks over and over and over and over.
TURBS is offline   Reply With Quote

gas, tank

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

» Virginia Campgrounds

Reviews provided by is not in any way associated with Forest River, Inc. or its associated RV manufacturing divisions.

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 06:34 PM.