Propane "Odorant" - Can The Odorant Concentrate?

[CADplans]

We have never run our propane tank as low as we have this year,, it has ALWAYS had at least 100 gallons in it, for the last decade.
(Yes, it is a pretty big tank, maybe 1,000 gallons)

Well,, it is spring, and we hope to be able to wait for the summer fill pricing special, so the tank is now using that 100 gallons,,

Is it possible the odorant in the propane has settled, concentrating? We have gas logs, kitchen stove, and shop heater,,
when burning, all of them seem to have a stronger smell of odorant,, The stronger smell just started in the last week or so,,

If it was just one, or even two appliances with the strong smell,, I would suspect cleaning of the burner might be the issue,,

So,, is it possible the odorant has concentrated??

 

[k0ua]

I think so, yes. I have noticed that too. I think what happens is the mercaptan oderant gets into the oily residue that propane leaves behind and is more concentrated down near the bottom of the tank where this oily residue byproduct accumulates. I don't have any proof of this, but it is what I think.

 

[jaydee325]

Go conservative for safety sake. Call your LP gas provider or a plumber to check for a gas leak.

I just went through smelling LP gas from our stove. I checked every connection from the supply valve behind the stove to the stove regulator with the usual soap solution check...nothing! Called an appliance repair shop. He came in with a "sniffer" and found a leak on the stove regulator.

 

[ericm979]

I've noticed the smell when our tank is low. Mostly in the kitchen near the gas cooktop.

 

[RandyT]

When the propane tank gets that low it has problem maintaining vapor pressure, so you may be experiencing low pressure at the burners causing incomplete combustion.

 

[coldsteelva]

For all intents and purposes, that tank is EMPTY. LP tanks are only filled to 80% at the FULL mark (allows for expansion) so you only get 800 gallons to start with and below 20% (which is EMPTY on the gauge), you begin to lose vapor pressure and get the stronger mercaptan smell; same thing with grill tanks, when they near empty, they stink. So in a 1000 gallon tank you really only get 600 useful gallons of LP volume. If you are at 10%, you are cutting it real close to empty; around here, if YOU run a tank out, the LP company mandates a leak test (at your cost) before they will refill.

 

[CADplans]

So in a 1000 gallon tank you really only get 600 useful gallons of LP volume.
If you are at 10%, you are cutting it real close to empty;

I have never heard that there was a "minimum" required in a tank,,
and it is hard to understand how the minimum could be more than 10 gallons,,

I do not doubt what you are saying,, at all,, in fact it is even believable.
It is just so different than all the liquid-gas vapor pressure stuff that I was taught,,,

 

[oosik]

Once on our outdoor bar-b-q I ran a ten gallon tank completely empty. At the very end I did smell the mercaptan odor. Completely went away when I hooked up a new full tank.

 

[Bigkrank]

I run both my 1000 gallon tanks to zero before switching. Never noticed anything or had an issue doing so.

 

[coldsteelva]

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