|
|
 |
 |
Frequently Asked Questions Concerning Air Products' BIP Technology
- Q: What is this new product, and what makes it different from any other gas product?
- Air Products engineered a purifier train as an integral part of the compressed gas cylinder. There is actually a purifier hanging from the bottom of the valve in every BIP cylinder. The purifier bed was designed with an excess capacity and breakthrough volume for the standard gas impurities. The valve is a patented design that incorporates features which protect the purifier bed against inadvertent back filling and contamination.
We condition each purifier and test its performance during conditioning. After installing the purifier in a cylinder and filling the cylinder, we test selected cylinders to demonstrate that the purifier meets the listed specs of < 10 ppb for O2 and < 20 ppb for H2O. The testing verifies the performance of the purifier in terms of these specs.
This "built-in purifier" guarantees the same and usually better purity gas at the valve outlet as your GC receives from your in-line, external purifier train.
- Q: Who makes the purifier?
- Air Products manufactures its own purifiers.
- Q: What is in the purifier?
- The BIP purification media and preparation are proprietary information.
- Q: Do you regenerate the purifier every time you refill the cylinder?
- No, that would make this product too expensive. Like your in-line, external purifiers, the built-in purifier will purify many cylinders of gas.
- Q: How long does the purifier last?
- Unlike the manufacturer of your external purifier, Air Products knows the impurity levels in the fill gas. This knowledge allowed us to set up preventive maintenance of the purifiers at forecasted periods..
- Q: What is that extra knob on the back of the cylinder valve?
- That's the cover for the bypass valve control on our patented cylinder valve.
- Q: Do you analyze every cylinder every time you refill it?
- Does your purifier vendor come to your lab and verify the performance of your point-of-use purifier every time you change a cylinder? Of course not, because the point-of-use purifier is designed with a certain capacity for the target impurity molecules But it is up to you to monitor its condition and to change it before it becomes consumed or saturated. It is also up to you to protect it from exposure to excessive levels of air.
The same principle of design capacity holds for the Air Products built-in purifier, but you do not have to monitor its condition or worry about protecting it from air. A built-in check valve and a residual pressure valve—engineering controls—protect the Air Products purifier from unintentional exposure to air.
Once we have established by several different tests that the purifier is working, we do not have to analyze every cylinder when we refill it because we know the capacity of the purifier and the impurity levels in the fill gas. We do have a QA program that tests a statistically significant number of refilled cylinders to verify purifier performance.
There is another reason we do not test every cylinder when it is refilled. Our intent is to take advantage of the purifier to lower the cost of this product.
- Q: Do you indicate on the valve or cylinder the current refill number?
- No, but in the U.S., we can track the number of refills of each BIP cylinder in our computer system because all of our Specialty Gas cylinders are bar coded, and every fill location has access to the computer database. For every built-in purifier installed in a cylinder, we maintain a database that relates the serial number of the valve to the bar code of the cylinder. Thus, the bar code of the cylinder allows us to determine the actual refill number from the fill history of the cylinder.
- Q: How can you guarantee that a customer does not back stream air or other contaminants into the cylinder and ruin the purifier?
- We guarantee that the refilled cylinders are exactly the same quality as the first fill for two reasons. First, the design of the purifier bed ensures an excess of capacity and breakthrough volume.
Second, the cylinder valve is designed to protect the purifier bed from inadvertent exposure to air or other materials. The cylinder valve is a patented design that incorporates a check valve and a residual pressure valve. The check valve prevents accidental back streaming into the cylinder while it is at the customer's site. It also prevents Air Products' technicians from filling the cylinder through the purifier. Additionally, the residual pressure valve closes at about 50 psig (3 barg), and guarantees a positive pressure of gas in the cylinder.
The patented cylinder valve also includes a bypass valve and alternate flow path which allow us to fill the cylinder without having to load the purifier from the top. We bypass the purifier to fill it, and you withdraw gas up through the purifier so all the loading is from the bottom up.
We also serialize each valve and purifier assembly to help us keep track of it.
- Q: What if I get a refilled cylinder?
- All of our BIP cylinders are refilled and reused, so you may receive a refilled cylinder but we guarantee the gas specifications because we verified the condition and performance of the purifier in terms of the quality of the gas with our initial manufacturing testing. We are not actually talking about gas purity but the verified and thus guaranteed performance of the purifier element.
Q: How does the BIP technology provide greater assurance of gas purity than a conventional purifier train?
BIP products provide greater assurance of gas purity for three reasons:
- Air Products tests the performance of every purifier;
- The BIP valve and the location of the purifier protect the purifier from inadvertent exposure to air; and
- Air Products tracks the number of refills instead of you tracking the number of cylinders of unknown purity that have been purified by your external purifier train.
BIP products are a step closer to the perfect gas supply.
Q: How is the BIP cylinder guarantee of purity different from that of a conventional external purifier?
We will answer this question with two questions and their answers:
- Does your point-of-use purifier manufacturer check the performance of every purifier element he produces?
Most manufacturers employ a statistical quality control method that permits the test results of a selected number of individual items in a lot to be applied to the whole lot. The odds are the purifier you install in your gas lines has not been specifically tested by the manufacturer.
In contrast, Air Products verifies the performance of each and every new purifier we produce.
- Does the purifier manufacturer know the quality of the gas feeding the point-of-use purifier?
No. typically, you don't either.
But Air Products does. It is much easier for us to guarantee the performance of a purifier than a purifier manufacturer because we control the feed gas quality.
We verify the performance of each and every purifier element we produce. We also know the quality of the feed gas. In contrast, the purifier manufacturer probably does not do the first and cannot know the second. The Air Products BIP system is under better control than the point-of-use purifier. It is a complete system available from one vendor.
Q: Do you give a Certificate of Analysis with each cylinder?
No. Because we are guaranteeing the performance of the purifier and not the quality of the fill gas, we provide a Certificate of Conformance. This level of certification guarantees on a per cylinder basis that the purifier is functioning and that the gas you withdraw from the cylinder meets the listed specifications, whether the cylinder is a first fill or a refill.
Q: Every gas company guarantees the product specs. What makes your promise any different from theirs?
We are actually guaranteeing the performance of the purifier; the quality of the gas confirms that the purifier is working according to its design specifications. From your perspective, the BIP technology puts us in the position of being able to guarantee the quality of the gas in every single cylinder. We have been able to sharply focus our guarantee on the individual cylinder—because of the purifier—instead of on a batch of cylinders through statistical quality control. No other company can do this without extensive and costly analyses. More than ten thousand helium and nitrogen BIP cylinders have been produced in Europe, and every one has passed QA testing.
Q: Why isn't the hydrocarbon spec as low as the O2 and H2O specs?
It's all perspective. The BIP helium THC spec is actually the same as the THC spec of our research grade helium. Remember that specifications are an indication of the highest possible concentration of an impurity in the gas; they do not describe the actual amount. The actual amounts of every impurity are typically much lower than the specs indicate.
In fact, independent testing by a government air analysis lab in Canada has shown that the C2-C7 hydrocarbon concentrations are less than their method limit of detection of low parts-per-trillion. We have confirmed that work using our own ppb-level volatile organic compounds (VOC) analytical system.
Q: What is the level of methane in BIP helium?
Methane is included in the THC spec. The typical levels of methane in our helium are an order of magnitude lower than the spec.
Q: Do I need my purifiers with this product to ensure one of your so-called "guaranteed" cylinders does not contaminate my instrument?
Our QA labs have never failed a BIP cylinder. Our guarantee of quality is at the cylinder level because we put a purifier in each BIP cylinder. BIP gas cannot contaminate your instrument.
You can keep your purifier train or put it into storage; it is entirely up to you.
If you want to keep it, you will get the benefit of extending your purifier lifetimes at least 100-fold. You can forget about changing the purifiers for the rest of your career, and at retirement, remind your successor to remind his/her successor to check them!
Q: What are the advantages of your purifier-in-a-cylinder concept versus my point-of-use purifiers?
Can you see our purifier? No, you can't. Will you have to be concerned about its maintenance? No. This is one of the advantages: you don't have to deal with or worry about the purifier. Air Products has taken responsibility for designing, activating, testing, and maintaining it. You don't have to do anything with the purifier; just forget it exists.
Perhaps eliminating the hard and soft costs of buying and maintaining your purifier train is also an advantage to you. The capital costs of your purifier train are absorbed in the price of this higher quality gas for a few dollars per cylinder. And so are the labor costs for maintaining it.
Because we give you a complete product in one package, you no longer have to deal with the add-ons of purifiers. And, for those who feel guilty about not doing regular preventive maintenance on your purifiers—yes, you know it is important but it usually takes a lower priority than getting data out the door—Air Products gives you the opportunity to remove that burden!
In those companies where the GCs have been distributed to the end user chemists and engineers, substituting BIP grade helium for the current system of low-grade helium and a purifier train is clearly an efficiency improvement step. It will allow the production of better analytical data with less work for end users whose focus is on the chemistry rather than on the instrument. This product can remove all the tasks related to purifier maintenance from the plate of a lab scientist and thereby improve productivity.
Finally, the higher the pressure, the higher the adsorbent capacity. Our purifier in the cylinder more effectively removes the impurities than the point-of-use purifiers because of the high cylinder pressure.
Q: Typically, the higher the purity specification, the higher the cost. Is this the same for BIP cylinder products?
No. We have priced this product in the range of products providing 99.9995% purity. Moreover, you may realize overall analytical cost savings because of the BIP cylinder features.
Q: What are the particle levels in the product gas?
Each purifier comes with a 0.5 micron frit (filter) on the top of the purifier bed to trap particles >=0.5 micron. Particle testing has shown that smaller particles are quantitatively removed during purifier conditioning.
Q: Can I get this product also qualified for ECD?
Yes, in Europe. It is not currently available elsewhere.
Q: How about the same grade of nitrogen?
Yes, BIP nitrogen is available in most of our global locations.
Q: I am comfortable with buying low-grade gas and using purifiers to clean up the gas at the instrument. It seems to work, so why do I need to buy this product?
We invite you to talk to us about the cost-of-ownership issues of using purifiers and low-grade gas. Our customers state that the BIP system saves them money and time and eliminates the hassle of purifier maintenance. Even small improvements pay dividends in data quality and productivity in the long run. These improvements allow them to provide superior final results to their customers.
Q: I keep my GC gases in a service corridor. I don't really trust the integrity of the plumbing from the cylinders to my instruments. That's why I use point-of-use purifiers. Why should I use BIP gases when I will have to keep my purifiers, anyway?
You may be right about the integrity of your plumbing, but do you know for sure? Do you use an indicating O2 purifier? If so how long does it take to consume it? Have you ever experienced breakthrough of hydrocarbons, O2, or H2O? You can determine the integrity of your system by monitoring how long your indicating purifiers last (they are typically supplied with documentation of their capacities for O2 and H2O). If you know the capacities, the gas flow rate, and duration of the time period from their installation to their consumption, you can calculate the concentration of O2 and/or H2O in your plumbing.
You can determine if your plumbing has significant leaks by conducting the straightforward pressure drop test. Seal the downstream end of the house line, pressurize it by turning on the cylinder valve, then turn off the cylinder valve while leaving the regulator set to its typical operating pressure. The rate of pressure decay of the regulator's high pressure gauge indicates the integrity of the plumbing.
Alternatively, you can install a flow meter close to the gas source and compare the flow rate at that point with the sum of the flow rates required by your instruments.
A leaking gas delivery system causes unnecessary, ongoing expense and can impact your analytical results. Air Products can advise you on how to find and repair leaks.
Q: Is this product available right now?
All BIP products are available in Europe. Helium, nitrogen, and argon are all available in BIP cylinders in many locations throughout the world. See the Specifications page in this website.
Q: It does not make sense to use BIP quality gas because of the large amount of air that gets into the regulator at every cylinder change.
This is why Air Products is also introducing the T-Purge Plus (Europe) and the T-purge and regulator assembly (Canada). These products allow you to purge the air out of the short section of tubing connecting the cylinder to your regulator, and protect the regulator from air contamination. Descriptive material is available elsewhere on this website.
Whether you use BIP gases or not, we advise you to add a T-Purge assembly upstream of your regulator to protect it from air incursions when you have to change cylinders. It is available as a separate item. | | |
|
 |
|
|
