Editorial: What’s in a Name? or Can Anyone Tell Me the Specs on "Seaford Grade Nitrogen"?

I guess some things never change. I remember back in the late ‘60s ... when I worked for one of the majors, and we were putting together our first "Specialty Gas Catalog." The first problem we struggled with was how to categorize the various purities of the gases that were to be included in the catalog.

We took a look at how other companies approached the subject (there were only two or three out there at the time), but nothing of what we saw made much sense or explained exactly what the gases listed were. Names attached to various gases included "PrePure," "Instrument Grade," "Extra Dry," "Bone Dry," "UHP," "Research Grade," "Coleman Grade," "Zero Grade," "CP Grade," "Technical Grade," "AA Grade Acetylene," "Lamp Grade Argon," and many others.

The real problem was that while two different companies may have listed the same name, their assays did not match. The assay for "UHP Helium" of one company, for example, was different from that of another. Another egregious example: "Research Grade Argon" from one supplier was listed as 99.9999% pure, while their "Research Grade Propane" was only 99.98% pure–an inconsistency in significant figures.

So how could we level the playing field to ensure that–at least most of the time– we would be quoting apples against apples instead of apples against oranges? Well, someone in our group (probably Al Barsocchi, since he was the most logical guy in the group) suggested that we call the purity of each gas by the assay–or the amount of "nines" in the specification. In other words, the "Grade" concept was used – 99.999% assay for helium was called "Grade 5.0," and 99.5% pure helium was called "Grade 2.5," and so on.

We were aware that this was not the answer to all of the problems. Some gases had to be produced for specific applications, in which parts per billion of certain impurities could prove deadly to a specific application. Grades, such as "ECD Grade" (Electron Capture Detector) could posses a relatively low total assay; however, it did not contain any of the impurities that would mess up an ECD detector.

(As an aside, at the time, we could not detect or measure the impurities at the low levels required for "ECD Grade." To overcome that shortcoming we ran the gas through an "ECD" test instrument to see if it was "good enough.")

The real problem with the "ECD Grade" was that it was not necessarily the purity of the gas that contaminated the detectors. The fault lay with residual amounts of the solvent used to clean the valves. If not properly or completely removed, these impurities would drive the detectors crazy, while the next cylinder filled on the same line at the same time–would be acceptable.

As I said in the beginning of this editorial –some things never change. Terminology that is suspect continues to plague our industry. In a recent issue of a trade journal, for example, a new product news announcement for "Fuel cell hydrogen" claimed that the product, " ... was low in ammonia, carbon monoxide, and sulfur compounds, which the supplier claims would hurt the catalyst-coated membranes inside the fuel cell." (Ed. note: Depending on the process used to produce the hydrogen, these impurities might exist.)

So the real problem persists–that of knowing what you are competing against or what the customer really needs for his process. I remember one story about a salesman who was trying to get into an account. He was asked to present a quote on "UHP" Argon. After he had submitted the quote, he made a follow-up call to see how he had done and was told his price was way out of line. What eventually came to light was that the current supplier’s UHP Argon was assayed at only 99.998% purity, while the salesman’s specification for a gas with the same nomenclature was assayed at 99.999%.

What is the answer to this conundrum? Well, aside from just plain old experience, I guess the best tact to take is to ask questions. When someone calls and asks for "Research Grade Propane," it is likely that that is what the current supplier calls the propane he is supplying. So you either need to know who that supplier is (and therefore what his specification is for that Grade of gas), or you simply ask what purity in "9s" the customer is looking for. Better yet, what are the impurities that will be bothersome or dilatory. But you had better know what your own specs are first. And if you are real lucky, you may make a friend for life by being able to supply that customer with a less expensive grade of gas, but one in which the level of contaminants is below the level that affects his application.

In one case, way back in the ‘70s, someone called and asked for Grade 7.0 Nitrogen (which we did not have at the time, but knew who did). So we told him we could get him a cylinder of Grade 7.0 Nitrogen, but it would cost about $800.00. To make sure he was asking for the right product, we asked him what contaminants the nitrogen might contain that would adversely affected the process to which it was applied. It turned out that the customer was most concerned about the oxygen level, not the argon level, which was the apparent concern. Argon is much more difficult to remove and that is why the cost for the Grade 7.0 Nitrogen was so high. Next we asked what level of oxygen could be tolerated. The answer was 10 ppb (parts per billion, which at the time could not be seen analytically). As a result, we suggested that we fill a cylinder of nitrogen through a high pressure purifier that would theoretically remove the oxygen to the acceptable level, and also pointed out that we would supply him with a cylinder of that nitrogen for about $100.00. We knew that the process to which it would be applied would quickly indicate if our solution was good enough. If not, we had at least tried. But if it did the job, we had a customer for life.

So I guess the best advise we can offer is, aside from having a thorough knowledge of your own products, you also need to know those of the enemy almost as well. As sort of a reward for your having read all of the above, we would like to offer a free one-year year subscription to The Specialty Gas Report to the first person who sends us what the specification was/is for "Seaford Grade Nitrogen." Also, a second one-year subscription if you can tell us how or why it was produced.