Alok,
>Praxair use CS pipes for oxygen!
Even shell stadard has CS in Oxygen service. But it has velocity limitation.
Above certain velocity, friction due to protruding welds, gaskets or impingement
on elbow walls, dead ends etc could be some of the few ingition sources. The
ASTM codes i mentioned before explains it all.
>Till now I never heard of any incidents?
Well, my previous client had a fire incident in SS oxygen line. (near Isolation
valve) That has multiple reasons.
Delacruz,
>CS will burn when in pure oxygen service under the right condition.
Quote from ASTNG94:
Most materials in contact with oxygen will not ignite without a source of
ignition energy. When an energy-input exceeds the configuration-dependent
threshold, then ignitionand combustion may occur. Thus, the material’s
flammability properties and the ignition energy sources within a system must be
considered.
Quotes from other codes:
Inherent safety: Oxygen systems shall be designed selecting materials that are
ignitionand combustion-resistant at the maximum expected operating conditions..
Safe oxygen
systems must include designs for preventing leaks, eliminating ignition sources,
establishing and maintaining a clean system, avoiding cavitation, and preventing
resonant
vibration.
Two lines of defense: In addition to the inherent safety features, at least two
failureresistant, independent barriers shall be provided to prevent a given
failure from
mushrooming into a disaster. Thus, at least two undesirable, independent events
would have to occur simultaneously under either normal or emergency conditions
before there
would be a potential danger to personnel or major damage to equipment and
property.
Despite its apparent innocence in many instances, oxygen is a serious fire
hazard. It makes materials easier to ignite and their subsequent combustion more
intense, more complete,
and more explosive than in air alone.
Rgs,
Umesh Ken.,Senior Piping Project Engineer,
BECHTEL AUSTRALIA, Brisbane, QLD, Australia
Favorite quotes:
1.. "Our lives begin to end the day we become silent about things that matter" ........... Dr. Martin Luther King, Jr 2. "Ones dignity may be assaulted, vandalized and cruelly mocked, but cannot betaken away unless it is surrendered".....Michael J. Fox 3. "Life moves pretty fast, if you don't stop and look around once in a while you could miss it" - Unknown
Praxair use CS pipes for oxygen! Till now I never heard of any incidents? So it
trickles down to specs,welding, etc
regards
alok dubey
CS will burn when in pure oxygen service under the right condition. The statement was taken from page 3 of the The Pressure News (ABSA) - vol 6, issue 4, Dec 2001. A copy can be downloaded from the Internet.
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[Non-text portions of this message have been removed] Received on Mon Feb 04 01:37:00 2008
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