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Up Topic Welding Industry / Welding Fundamentals / Torch maintenance.
- - By Superflux (****) Date 12-25-2010 02:27
The LOX thread seemed to get more into rosebud issues, so....
I was going to call this "Torch Tips" but that seemed somewhat too punny.
When a torch pops, the flame has extinguished downstream (outside) of the tip (due to that lower velocity previously discussed) and has progressed upstream...INTERNALLY! Now once this happens, damage results inside the torch tip (rosebud, blowpipe/brazing tip, or cutting head). Oftentimes this damage (and resultant carbon build up) to gaskets and seating surfaces is a non issue...until the next pop, and the next...Once it happens, the torch is more susceptable to backfires and so happens more often and easier.
NMWELDER, Is acetylene harder to light??? Can't say I've noticed any difficulty as you describe. All problems I've had to adress seem to iron themselves out when proper procedures and equipment are used and followed.
Parent - - By Superflux (****) Date 12-25-2010 02:45
There is a lot of engineering that goes into the design of torches and tips. All these components require proper cleaning and occasional replacement.

Tip maintenance.
The torch and all its accesssories is one of the most unappreciated technologies in the Welding trade. After cutting tips are "broke in" (ie. banged around and used as a slag hammer), the end gets a bit ragged and needs to be squared up. The fastest way is to file it flat and then rebore the holes with a tip cleaner key set or micro-drills.
There is a nifty little doo-hickey called a "Tip Nip". Factory Victor brand tips have a slight counterbore to them instead of being perfectly flat. Kinda like a target crown on your varmint rifle. The Tip Nip device does a good job of reconditioning that profile. for all applications.
Parent - - By welderbrent (*****) Date 12-25-2010 16:30
Very good topic line Superflux.

Along with the Tip Nip idea and all your advice for clean tips, When using Propylene and other fuel gases with the two part tips you also need to take good care of your tips.  The inner part can be carefully cleaned by hand with a SS brush to clean the flutes.  Also a very thin blade to straighten any that have twisted from too much pressure when tightening.  (Some brands will twist almost every time you put one on, bad design in my opinion because other brands almost never twist.)  Then carefully use a flat fine pitch file to flatten the end of the tip as it will get rounded corners and not burn as well as it should (actually my first step, then clean the flutes, then clean the oxy port).  Lastly I use the tip nip on the outer jacket to flatten the tip and a small round file to clean out the hole.  Be very careful to just clean.  Do not remove much material.  Once you change the dimensions it will not burn as clean.

Using this process I can use these tips for quite a while and get very clean cuts.

Have a Great Day,  Brent
Parent - - By DaveBoyer (*****) Date 12-27-2010 03:32
Brent, I take it You are cutting with propalene. I saw a guy demonstrating propalene, it looked really good. A friend tried it, and He liked it, but can't get it on St. Crox where He lives. What brand name/company are You getting it from? I have an empty cylinder from "High Purity Gas", I am not sure if anybody in My area will fill it.

All in all, how do You like it, Whoose tips are You using, and what does it actually cost?
Parent - By welderbrent (*****) Date 12-27-2010 14:19
Dave, Holiday Greetings!!

I love it.  I have used it since I was at LeTourneau repairing Log Stackers in OR.  We used Airgas as our supplier up there.  Down here in AZ I am using Praxair. 

I am very pleased with the way it burns, safety (not worried about laying it down or using over 15 lb), price (cheaper that Acet in cost per hr), and more.

Some companies are using other trademark names but usually you can just ask for Propylene and they know what you want. 

I have gotten tips from American Torch Tip on line as well as from Praxair.  Don't know the brand name of the Praxair tips but have not had any problem with them.  Instead of listing the good ones I will get the brands of the ones I have had problems with. 

I will have to look up the pricing.  It will vary by supplier, region and volume.  But I can get you close.

Have a Great Day,  Brent
Parent - - By Lawrence (*****) Date 12-27-2010 18:03 Edited 12-27-2010 18:07
Dave,

We use propylene for our manifolded cutting stations.  Track burners, hand cutting and beveling and heating..  It works quite well.. In my opinion equal to acetylene in everything but gas welding (which it won't do).  We used to use Mapp in this system but Mapp became unavailable in our region about 2 years ago.  I use Victor and Smith tips because I inherited a several different torch bodies (two piece tips on the track burners). I think both are excellent, no preference.

Safety note for the rest of the folks:

Do NOT attempt to use Mapp/Propylene or Natural gas cutting tips with Acetylene gas..  Cutting tips (especially two piece tips) are not interchangeable from alternative gases to Acetylene.  Acetylene has a much greater propensity to burn upstream, meaning it can cause flashback inside the torch much more easily if a starvation condition or overheat occurs.  If you make the switch.. Buy new tips and use the flowrates recommended by the manufacturer.
Parent - - By ctacker (****) Date 12-27-2010 21:00
Excellent Advice us old-timers tend to think everyone should know already, but to someone learning is very important!
Parent - - By JMCInc (**) Date 12-28-2010 05:59 Edited 12-28-2010 06:05
Worked with an old timer who used a propane/oxy set up. His cuts looked like they had been done with a plasma cutter. He said that it takes longer to heat the metal initially but once the cutting begins it's slick as a whistle. I can't argue with the results that he was getting. I was also present when a person tried to run acet through a lp tip. The guts of the two part tip were melted instantly.

The salvage yard here uses propane/lox. The yard foreman said they'd go broke burning acet all day.

Jon
Parent - By DaveBoyer (*****) Date 12-29-2010 03:38
The auto frame plant I worked at had an Airco optical tracer torch for plate cutting. It used propane and oxy from bulk tanks. The cuts were really good, even on 6" thick plate.

The machine was capable of cutting up to 12" thick, and We had plate in stock up to & including 12". The Oxy line from the bulk tank was only 60 PSIG, so for plate thicker than 6" manifolded cylinders had to be used. This was poor planning on the part of the company. We were discouraged from using plate over 6" thick [unless absolutely neccesary] due to this problem.

The oxy & propane were piped around the plant, mostly for running rosebuds. I don't believe there were regulators at the heating stations, they just used the line pressure.
There should have been a seprate higher pressure line to the burning machine, but there wasn't.
Parent - - By welderbrent (*****) Date 12-29-2010 18:18
If I remember correctly, Propylene burns about 500* cooler with same size tips as Acet.  Thus, when pre-heating before the burn it takes a couple moments more to get the steel warm enough. 

Dave, the plant can basically keep all stations from using too much oxy by setting it at a master regulator.  Some people think if a little is good a whole bunch is better.  Like trying to get more pressure in a fine stream out of a water hose.  At a certain point it reacts opposite and broadens and shortens the stream instead of keeping it thin and long.  When applied to the burning machine, I find I can often run lower pressures for both my fuel gas and my oxy than when burning free hand.  The machine is smoother and very consistant so requires less heat and pressure to accomplish the same task.  And that was using a four torch machine on everything from 1/4 through 4" plate and including much T-1 steel for heavy equipment.  Ran an Oxy six pack and a 100 lb Propylene.  We didn't use it consistent enough to warrant the Liquid Oxy tank and the company didn't want to pipe it throughout the shop to be used at every work station in order to utilize the process. 

Have a Great Day,  Brent
Parent - By DaveBoyer (*****) Date 12-30-2010 04:03
The machine I described had multiple torches, but most of Our parts were one of a kind. I don't know if the operator had the confidence to run more than 1 torch when there were duplicate parts.

It was a good machine, but being older and big [10'x20'] it sold cheap when the plant closed. Another local company got it.

The auto frame plant was a pretty big operation, employing 3,000 people at it's peak. They had bulk Oxy, propane & CO2 piped where needed. Our building, which housed the tool & die shop, machine shop and production machine shop wasn't plumbed for any of these gasses, We used cylinders for what little We needed in that building.

The plate yard and burning shed were located off of another building.
Parent - By 357max (***) Date 01-06-2011 03:45
Oxy fuel equipment requires alot of TLC and lots and lots of "NO OIL"
Up Topic Welding Industry / Welding Fundamentals / Torch maintenance.

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