Quality of Oxygen for Gas Cutting

By Asogan Date 03-27-2005 11:19

What is the minimum quality of Oxygen required for Oxy-Acetylene cutting of steel?

Normally industrial oxygen is prepared by liquifaction of air or by Air seperation. Air seperation produces about 93% purity oxygen I undersatnd, compared to 98% or more by liquid air process. Is there any problem in using 93% oxygen produced by Air Seperation for cutting steel?

By Lawrence (*****)

Date 03-27-2005 18:38

the lower quality will have a negative effect

By Asogan Date 03-28-2005 09:58

Thanks Lawrence.

What I would like to know is with 92-93% Oxygen, if satisfactory cuts can be done.

I am a technical manager in a shipyard in Cameroon - West Africa. We have two sources who supply industrial gases. We get compalints from some workmen that oxygen supply from one company who produces oxygen by seperation process is not good.

At the same time, number of other leading Offshore companies use the same gas and the supplier has no complaints from them.

So what I want to establish is, if the probelm is operator related or product related. There could be some standard minimum requirement of purity stipulated by say BS, ISO, DIN etc.

If someone could highlight, could be very helpful

Asogan.

By Lawrence (*****)

Date 03-28-2005 15:45

Hope this is a good lead.

AWS Welding Handbook Ninth Edition Vol 2

Chapter 14 Page 609
" The oxygen used for cutting must have a purity of 99.5% or higher. Lower purity reduces the efficiency of the cutting operation. For example, a 1% decrease in oxygen purity to 98.5% results in a decrease in cutting speed of approximately 15% and an increase of about 25% in the consupmption of cutting oxygen. The quality of the cut is impaired, and the amount and tenacity of the adhering slag increases. When oxygen purity is below 95% the familiar cutting action disappears, degenerating into a melt-and-wash action tha is usually unacceptable."