how much propane??

[porklvr]

alright here's my question....

I have a 15lb tank and used it for about 6 hours running my GOSM to smoke some ribs.  I'm gonna be putting some butts on in the morning and don't know if what i have will get me through.  my butts are about 7lbs each.  I only have one tank, so do i need to try and get another one or do you think this one will do it for this smoke??  i'm worried it won't but have no experience with propane at all.  thanks for your help!!  Need to know what to do asap bc if i need another i need to move now. 

 

[bpopovitz]

Take a look at the tnk and you should see something that says TW - That is the tank weight of an empty tank.  Weight the tank and subtract the tank weight.  That will give you your propane weight.  Dividie that by 4.23 to get your gallons of propane.  Then multiply that by 91500 that will give you your BTU's remaining.  You will need to know your burner rating in BTU then you can divid by that to give you the hours remaining.  Example

TW - 17.2

Current weight - 22

Propane weight - 4.8 LBS

Gallons of propane (weight /4.23) 1.134752

BTU remaining(gallons *91500) 103829.79

Hours remaining (BTU remaining / burner rating, in my case 15000) - 6.92 hours

I hope this help.  I strung this together froms posts here and some more research on Wiki-pedia