[TheForge] Re: repost of propane cylinder cutting

[Terry L. Ridder]

hello;

i have debated this numerous times with the propane service
companies here. i tend to believe that the slight amount of
rust internal to the cylinder is what has absorbed the propane
and/or the mercaptan. they still say it is the cylinder's steel.
i guess it is really a mute point since i have seen it where a
cylinder has been purged with water, dish detergent, and bleach,
shoot a four foot flame out the value hole when a oxy-fuel torch
just pierced the cylinder. 

i am still working a design to cut the cylinders with a basically
a large pipe cutter. many cutting wheels in a roller chain straped
around the cylinder. have not had much time this year to work on it.

i did see one a fellow made that used a roller chain to guide the
oxy-fuel or plasma torch around the cylinder. a trolley with air motors
driving the wheels followed the roller chain. the trolley holds the
cutting torch. 

On Mon, 25 Nov 2002, Mike Spencer wrote:

mike> 
mike> Thanks, Terry.  Saved as a manpage for easy access.
mike> 

terry> scrap lift truck cylinders, roofer cylinders,
terry> plumber cylinders are different cylinders
terry> and need to be treat differently. i will cover
terry> those in a separate post.

mike> 
mike> Didn't know that.  I'll watch for the post.
mike> 

terry>    propane cylinders absorp some of the ethyl
terry>    mercaptan that is used to give propane an
terry>    odor. they also absorp some propane.

mike> 
mike> I'll take your word for this for the sake of safety but I don't
mike> understand it.  Wood is a porous composite.  Sintered metals are
mike> porous.  Plastics can adhere monomolecular layers of (even partially)
mike> non-polar substances.  I don't get how sheet steel and "absorb"
mike> relatively simple organic stuff like propane or ethyl mercaptan.  Is
mike> this related to the (potential) formation of highly sensitive and
mike> explosive metal-acetylides?  Doesn't seem to me like it would be
mike> because the unique triple bond of acetylene is missing.
mike> 
mike> - Mike
mike> 

and, yes that is 'the fish'.

-- 
Terry L. Ridder ><>