On Jul 13, 11:51Â*am, jcarlyle wrote:
On Jul 13, 12:39 pm, Darryl Ramm wrote:

Maybe more useful discussions on saftey are not related to the O2
labeling but the handling of the cylinders, trans-filling procedures,
maintenance and servicing etc. I've seen some pretty blase/scary
handling of O2 by glider pilots, old steel bottles last inspected God
knows when, etc...

I'd welcome some discussion on the topics you mention. That would fill
a real need for pilots like myself who don't often use oxygen.

One thing I'm curious about is the hydrotesting requirement. If one of
the legendary arguments for using "aviation" oxygen is its low
moisture content (debunked above), then:


From talking with a hydrotesting shop owner as I waited for a bottle
to be serviced.

1. Â*how is water completely removed from a cylinder after
hydrotesting, andl

They evacuate the bottle to a high vacuum while mildly heating it.

2. Â*how can a user be assured that no corrosion will be created in his
cylinder as a result of hydrotesting?

The bottle is borescoped after hydrotesting with the valve removed.

BTW, I think Mythbusters had a program on what happens if you break
the valve off a high pressure cylinder. IIRC, reality didn't quite
live up to the urban myths.

Here's a deeper explanation of stamp codes.

Oxygen cylinders are marked to designate the type of cylinder, maximum
fill pressure, hydrostatic test date, inspector, manufacturer, and
serial number. The marking are normally stamped into the shoulder of
the cylinder. The hydrostatic test date and inspector mark indicate
when the cylinder was last tested and who tested the cylinder. Most
oxygen cylinders are required to be tested every 5 years. This test
ensures the cylinder can safety hold the maximum fill pressure. There
are two other markings which are sometimes found on these cylinders.
The plus (+) sign located after the test date designates that the
cylinder can be filled to 10% above the pressure stamped on the
cylinder. The five-pointed star in the same location designates that
the hydrostatic test date has been extended an additional 5 years. A
cylinder with a five-pointed star would need to be tested every 10
years.

Vertical Alignment:
DOT-3AA 2015
1234567
XY Corp
8 ® 08 + ۞

Horizontal Alignment:
DOT-3AA 2015 1234567 XY Corp 8 ® 08 + ۞
DOT = Department of Transportation
3AA = Seamless alloy-steel cylinder
2015 = 2015 psig fill pressure
1234567 = Serial number of cylinder
XY Corp = Manufacture of cylinder
8 ® 08 = Month and Year, in this example, August 2008, the symbol of
the inspector is commonly placed between month and year (® used as
example only)
+ = Cylinder maximum fill pressure can be 10% above 2015 psig or
2216.5 psig
Ûž = Cylinder may be tested every 10 years versus the standard 5 years