Acetylene welding question

I sometimes to get an occasional pop while I am welding. BUT, what is it when I get rapid machine gun fire pops that continue until I pull my torch
away. Using Victor gauges, Victor torch & tip (#3). Gauges are set to 7pis acetylene and 10 phi oxygen. Note: I am trying to heat (so I can bend) and not weld. BTW, same thing happens when trying to use a Rosebud tip, except much worse. I do use higher settings with the Rosebud.
Clues of what I am doing wrong appreciated.
Thanks, Ivan Vegvary
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Ivan Vegvary wrote:

I think your acetylene pressure is too high. Magic numbers are 3 and 10 psi at South Seattle Community College. Even though your tip is a little bigger than theirs, I'd try cutting it back some.
Also, remove your torch tip, take a magnifying glass, and look very closely at the O-rings.
Here are the first few lines from the Victor welding tip chart. Make sure you are reading these in non-proportional font (i.e. Courier or equivalent):
Victor Welding Tip Size And Application Data
TIP DRILL LENGTH OF OXYGEN ACETYLENE ACETYLENE METAL SIZE SIZE AVERAGE PSI PSI CFM THICKNESS INNER FLAME CONE MIN MAX MIN MAX MIN MAX ------------------------------------------------------------------- 000 75 7/32" 1/2 2 1/2 2 1/2 3 UP TO 1/32" 00 70 7/32" 1 2 1 2 1 4 1/64"-3/64" 0 65 3/8" 1 3 1 3 2 6 1/32"-5/64" 1 60 3/8" 1 4 1 4 4 8 3/64"-3/32" 2 56 3/8" 2 5 2 5 7 13 1/16"-1/8" 3 53 3/8" 3 7 3 7 8 36 1/8"-3/16" 4 49 5/8" 4 10 4 10 10 41 3/16"-1/4" 5 43 1" 5 12 5 15 15 59 1/4"-1/2"
Grant Erwin Kirkland, Washington
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The tips are getting too hot because you have them too close to the work piece and/or in a "corner" where too much heat is reflected back on the tip.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
David Courtney wrote:

Or you're not running a big enough flame.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Get the tip chart and set your pressures from that, I think they're too high, myself. Tip chart will also get you suggested max thickness you can work with each tip size as well as flow rates per hour of gases used. Gratis from your equipment supplier, usually, or try the web site. Need more heat, get a bigger tip, don't just crank the pressures up.
My snapouts went away after polishing the tips. Keep them clean and they don't pick up too much heat. If they look like they've been used for mixing roofing tar, it's way past time to clean them. Black junk soaks up heat, heat decomposes(explosively) acetylene. Decomposed acetylene leaves behind a lot of carbon. And round and round we go.
Stan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The rapid fire is what happens when the tip itself gets hot enough that the gasses combust inside. The solution is to cool the tip in water or use a larger tip.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Thanks everyone!!!!! I appreciate the answers. All consistent for a change.
Ivan Vegvary
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.