On 5 Feb 2006 14:18:32 -0800, "jcarlyle" wrote:

In the United States pressure vessels must be certified to either DOT
or ASME standards. If a pressure vessel to be used in the USA does not
have either DOT or ASME certification, it is illegal to use it, much
less to fill it.

John, can you provide support for that? I'm in the hydraulics
industry, and we have charged (and recharged) accumulators and gas
bottles for years that are neither DOT nor ASME approved. These are
not always old, nor small ... I worked with one gas bottle pressurized
to 3800 psi by N2 which cycles between 4200 and 4800 every 50 seconds
.... with a volume of over 200 gallons. I just commissioned a system
with 2 new (2005 manufacture) 32 liter accumulators that were bought
by others from others, but to which I pressurized. I "trusted" the
ratings stamped on the shell, but they had no approval stamps
(manufacturer offers ASME or TUV as options; neither engineer nor user
requested it). Am _I_ breaking the law?

We constantly wonder when pneumatic cylinders are going to be
considered pressure vessels in the USA; the PED (Pressure Equipment
Directive) of the EU already has criteria.