Vacuum Rupture Disk D- CSI Outer Leak

Another client met me at the door saying, “Your timing is perfect. Come back to the plant and see what you can tell us about this freshly rehabbed vessel that we are having some trouble filling.” The problem was apparent from about ten feet away. We walked on up to the vessel and found a neat hole (about welding wire diameter) that went through the plastic rupture disk cover, the “Do Not Remove” warning and apparently through the rupture disk. The plastic cover and label were removed to reveal the expected “sucked in” rupture disk. This was obvious tampering and one of the few times I’ve seen it done through the rupture disk cover.

Vacuum rupture disks plastic covers are put on cryogenic liquid cylinders both to prevent tampering and to protect the very thin disk material from welding and cutting sparks and corrosion. A supplier who is able to consistently assure that all liquids go out with rupture disk covers in place is both protecting their assets and providing a ready visual indicator for drivers to help with spotting potential problems.

Many of the liquid oxygen, argon, and nitrogen bottles that come in with blown rupture disks are clearly tampered with. Spotting problems at the user site and documenting them helps with the possibility for recovering the cost of repairs for damages.

A lot of people believe that “if you take care of the nickels the dollars will follow.” Here is a case in point.

Blown Rupture Disk C- CSI Inner Leak

Delivery Company Y makes a delivery to my shop. Two weeks later I call them and say I just got to this box, it is damaged and I want to place a claim. Unable to stand the sound of their laughter I hang up. Much is the same when a gas supplier tries to call their client two weeks after picking up liquid cylinders to say that some of them are damaged and they are going to bill the customer. The difference is that the reaction from the client can be a little rougher than laughter.

Having alert drivers who pay attention to what they are loading at pickups, note damage found and get customer signatures is priceless. Take for instance a cryogenic liquid cylinder that has a bent handling ring, piping and a dent on the head. Looking a bit further the driver finds that the vacuum rupture disk is blown out. This is pretty simple. The liquid cylinder has been dropped and there is now an inner leak at the neck or some other point. The contents (oxygen, nitrogen, argon or CO2) has escaped into the annulus, built pressure and blown the rupture disk.

Now the cryogenic liquid distributor is confronted with either a costly repair $750 to $1000 or more or replacement of the liquid cylinder $2000 to $3000 or more. In the case of a larger “micro-bulk” vessel that is set down too hard and snapped a neck connection the replacement cost can be well over $10,000 to $20,000. And- it is really hard to tell if that happened at the customer’s site or the fill plant without documentation at pick up.

Note that all inner leaks are not the result of abuse. Some do occur due to manufacturing or design issues, but the chance of recovering or even sharing costs with users are greatly diminished without documentation…… and reasonably so.

Medical Oxygen Wakeup Costs Reduction D

Outsourcing provides many homecare companies the option to provide liquid oxygen where they otherwise would not be able to. For others already delivering liquid it can mean increased profits and the ability to focus energies on patient care and other parts of their business. Outsourcing is a big topic containing enough twists and turns that we’ll come back to it with more extensive discussion in later posts.

Some people wonder how a subcontracting company can provide liquid medical oxygen delivery at a rate low enough that they and the principle homecare provider can both make a profit. And this is a good question as there is no guarantee that every situation has a mutually beneficial solution. Also, even where there are standard conditions that would seem to be ideal there are other voiding conditions. This is particularly true in smaller or more remote areas where there is not an adequate concentration of users.

One place the outsourcing model works best is where the delivering company (outsource provider) can enjoy increased economies of scale by adding stops to daily routes. It is pretty easy to see that a lot more positive cash flow is generated from a route that does 16-20 stops in a day than a route doing 6-10 stops. Picking up subcontract deliveries can make a huge difference in profitability even if the incremental additional deliveries are provided at lower rates than others. This is much like the pizza delivery model where more actual profit might be made from the second pizza at $6 than was made off the first pizza at $12.

The point of all the ideas we have covered is that it is possible in many cases to increase positive cash flow generated by liquid medical oxygen delivery. And, the availability of liquid delivery can also generate other positive referrals and revenue streams for homecare providers that they would otherwise be missing.

Medical Oxygen Wakeup Cost Reduction C

Several suppliers in the U.S. are now offering innovative remote filling services for truck mounted medical liquid oxygen delivery vessels. A few are actually meeting delivery trucks in the field and providing a sort of “in-flight refueling” service that allows homecare oxygen providers to extend their work day without a trip to their main bulk oxygen supplier for refilling. Other suppliers are going to their homecare liquid oxygen delivery client's sites and filling their trucks after hours so that drivers are able to go straight out on their routes in the mornings.

This is a true “value add” arrangement providing the best of both worlds with increased revenue generated for both the bulk or mini-bulk supplier and the homecare oxygen delivery company getting filled. Granted, there is no free lunch and both parties have cost benefit decisions to make related to return on investment and potentially higher direct costs for liquid oxygen. The potential off-set is savings generated from reducing Waiting Time, Transportation, and Talent wastes.

There is a funny twist for cryogenic tank manufacturers in this Cost Reduction series pointed out by a friend: “The more efficient companies become the less need there is for new delivery vessels.” Sure. This is true. Likewise- the more cost-effectively homecare companies can operate the more viable liquid oxygen remains as a solution for respiratory patients and providers.

Flow vs. Pressure- Boiled Frog Syndrome

Customer Y calls in January to ask about problems with his cutting torch work. “I just don’t understand. In August, everything seemed to be working fine. Now we are extra busy and my guys just can’t seem to cut like we were. We’ve turned the pressure builders all the way up, but that just doesn’t seem to help.”

Visiting, we find that several things have changed since August. He is, in fact, a great deal busier and now has 3 to 5 torches running off a liquid cylinder where he previously had 1 or 2. They’ve moved up to larger bore cutting tips and it is colder outside. All have combined to reduce the flow of vaporized oxygen gas that he is able to get to each torch.

This is a common and often misdiagnosed problem- especially where changes have occurred gradually or where users have switched sources from high pressure oxygen cylinders to cryogenic liquid oxygen. In many cases, the attempted solution is to increase pressure by going to high pressure liquid cylinders or cranking up the pressure builder on what they have. This sometimes makes the problem even worse by overflowing available ambient vaporization.

If the real issue is inadequate flow of gaseous molecules then the solution is often as simple as adding additional vaporization downstream. Very high use applications such as feeding multiple oxygen lances or large cutting tips might require you to link multiple liquid cylinders or go to a larger tank.

- Photo provided courtesy of Oxylance, Inc.

Dangers of an Improperly Decommissioned Liquid Cylinder

Disasters are rarely caused by a single action or event. More often than not they result from a series of small failures that culminate in a whopping show stopper. You might have already seen the attached presentation. If not- Hit the link below and take a moment to see just how wrong things can go when people “rig” equipment, disable safety devices and use it in ways not intended.

www.cdc.gov/eLCOSH/docs/d0500/d000585/d000585.ppt

Cryogenic News Introduction

Thank you for sharing a moment or more of your time to check out this blog. It is my wish that you will find some of the information shared to be helpful, interesting, enlightening or even occasionally inspiring.

Cryonews is focused on items of interest to cryogenic industry suppliers, users, and students taking into account the wide diversity of people and applications in the field. Liquid Oxygen, Argon, and Nitrogen have an incredible number of uses in areas from Medical Oxygen in Hospitals, Research and Homecare to Manufacturing, Construction, Welding Jobs, Demolition, Food and Beverage Production, Harvesting, Special Effects and more. In turn, new posts will intentionally traverse a pretty wide open course going wherever the light shines that moment. And there will be frequent posts with no seeming relevance delivered guilt-free.

This blog is intended as a source for industry news, tips, and insights. Questions, ideas, and links that might be considered worthy of note will be valuable and appreciated. Inevitably, we’ll find that others are wondering or interested in the same things. I'll endeavour to provide responses that are accurate and avoid “the sin of being booooring.”