Cryogenic & High Pressure Nitrogen Gas Options for Laser Feed

A client called yesterday regarding problems he was having with a nitrogen feed for a laser system. The system has been in service for a few years and working fine until recently. Something had changed. The change turned out to be different material being cut which changed the feed gas flow and pressure requirements. The best solution turned out to be temporarilly supplying the laser system with high pressure gas 16-packs since the user's need is short-term and requires a relatively low total volume of nitrogen.

The link below is to an article I ran across while doing more research. It helps define some of the issues and options related to nitrogen feed options for laser cutting.

http://www.thefabricator.com/LaserCutting/LaserCutting_Article.cfm?ID=1741

E-mails with links to other helpful information on this subject are welcomed.

Tried a GOrilla; Bought Fifteen More

Hope's Hope asked if there is more to this article than the published 6-Word Novel. More expertly written 6-Word Novels such as Hemmingway's "For sale: baby shoes, never worn" obviously do a better job of telling their story.


"Tried a GOrilla; Bought 15 more" is also true which hurts the "novel" classification.


This is the story of a gas distributor who tried something new and used it as a great tool to exploit a niche. The point here is that experimentation and innovation is alive and well in the gases industry. And- we are in one of those great times when people can do things that allow them to write their own success stories by using "the liberating force of adversity" to their advantage.


Also- candidly- it is a lot of fun to help others succeed and then celebrate their accomplishments.

A Six Word Cryogenic Success Story

Tried a GOrilla; Bought 15 more.

Liquid Only Liquid Cylinders- Cruddy or The Good Stuff?

A gas distributor took me on a tour of their facility and showed me where they keep their good liquid cylinders and where they keep those needing repair. On a side of their yard was a third group of about two dozen liquid cylinders that I pointed out and was told they were scraps. When asked if they were inner leakers or otherwise beyond repair the client said essentially "Oh, no. They are just those cruddy old liquid-only vessels. No one uses them anymore."

Another distributor took over the business at a very large mixed use facility with a number of labs using nitrogen liquid. Scattered about the labs was a large number of liquid-only style liquid cylinders. The client was told that instead of liquid-only vessels they would be getting "the good stuff" all through their plant...... meaning VGLs.

Both cases share a pretty common perception and contributed to a belief among some users that vendors are somehow denying them top quality when they provide Liquid-Only liquid cylinders for applications where the only need is for nitrogen in a liquid form.

A counterpoint to this perception is the fact that liquid-only style 4L-DOT liquid cylinders will contain nitrogen in a liquid state longer than a same sized liquid cylinder with Gas Use capabilities.

Why?

Absent the gas use function, Liquid-Only liquid cylinders do not have Gas Use Vaporization Coils, Pressure Building Coils, Regulators and other heat syncs that transmit energy (heat) into the liquid and cause it to boil off more quickly.

The funny thing is that the myth of Liquid-Only vessels being "cruddy" is so pervasive that a large percentage of people are unaware you can even still buy Liquid-Only containers. And even those that do know you can are reluctant to get them due to backlash they often get from users who feel they are somehow being short-shrifted.

Paradigm shift?

LCCM Conversion- NOT

The photo above shows a modification done to a cryogenic liquid cylinder to convert from an LCCM pressure building/ economizer regulator to a more common style regulator.

This is not a manufacturer's approved modification and is a case where the possible risks likely outweigh any gain. Some of these risks include:

- the refusal of some or all repair centers (except the modifiying vendor's) to work on liquid cylinders that have been substantively altered from their original design. The potential liability resulting from the failure of a modified vessel is just not worth the minimal profit that might be made from rehab work.

- the possibility that knowledgeable end users might also consider these conversions to be unacceptable.

- the fact that liquid cylinders that are modified in this manner can never be returned to their original LCCM operation.

LCCM regulators are indeed expensive to replace, but most can be rebuilt. And- trying to convert to a less expensive regulator by substantially modifying an original manufacturer's design of a DOT vessel can have the appearance of a dime getting in the way of a dollar........

Adversity Liberates new GOrilla 1500

A post from a few weeks ago discussed "the liberating force of adversity" and the paradox of great innovation in difficult times. This week's release of the new West Cryogenics 1500 gallon GOrilla is another prime example. While this vessel has been on the books for development a long while now there was a major challenge in trying to work the design in between so many competing priorities.

Well- get a little break from the mad rush of things and see what you get......

Once again, West Cryogenics has managed to innovate at a level not regularly matched. The new GOrilla will include all the standard features found on the existing 500 gallon and 850 gallon GOrilla portable cryogenic vessels:

- Combo Top Bottom Fill

- Robust Pressure Building System

- Road Relief Valve Allowing for Liquid Transport

- Gas Output with Economizer and External Vaporizer

It will also have an auxillary 2" liquid withdrawal line for those who want to add pumping systems for liquid delivery. Rated at 250psi mawp this vessel will afford flexibility to serve both gas feed and liquid delivery systems for liquid oxygen, nitrogen or argon. And- it can be paired up with its smaller 290 to 500 gallon cousins, cryogenic liquid cylinders or gas cylinders for an almost unlimited variety of Hospital and Medical Emergency Backup and Rapid Deployment applications or fitted with mixers for direct distribution of blended welding gases.

No- West Cryogenics does not enjoy economic downturns at all. But- once again- a little downturn has provided a great opportunity for innovative development.

There has been a tradition of using downtime to come out even stronger for the future and no one at West Cryogenics can see a reason to break that tradition this time.

Simple Set Screw Solution- Shrink Seal

Today’s suggestion: Shrink Seal the set screws on your cryogenic liquid cylinder pressure building and economizer regulators.

There has been a lot of emphasis in this post on the difference between flow and pressure. The primary focus of discussion has been to try and clarify the fact that higher pressure does not equate to higher flow. Point: Cranking up the pressure builder setting on your liquid oxygen, nitrogen or argon 4L-DOT liquid cylinders does little or nothing to provide higher flow and can cause a number of negatives……..

- Out of Balance Economizers,
- Broken PB Regulators,
- Excessive Venting and more.

Solution- Leave the set screw alone. The odds of this happening- It depends.

Make it harder to mess with the screw and you might find an ounce of prevention to be worth a pound of cure. Where necessary- Create consequences for tampering with pressure builders and you might deter even more tinkering.

Oh, and yes- West Cryogenics has been doing this for years and sells both shrink seal material and heat guns.

www.westcryogenics.com