Air Products speciality gases BIP® technology

Frequently Asked Questions

Concerning Air Products' BIP® technology


Q:  What is BIP® Technology 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 attached to 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 unique 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 specifications featuring impurities as low as <10ppb total hydrocarbons, <10ppb oxygen and <20ppb moisture. The testing verifies the performance of the purifier in terms of these specifications.


This "built-in purifier" guarantees the same and usually significantly 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 and tests its own purifiers using the highest quality purifier materials.

Q:  Do you regenerate the purifier every time you refill the cylinder?

No, that would make this product too expensive. The built-in purifier has a very large capacity that 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 allows us to set up preventive maintenance of the purifiers at regular 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 unique cylinder valve. This is never used by customers – it is only removed by Air Products during the filling process.

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. 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 any possible 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 comprehensive Quality Assurance program that tests a statistically significant number of refilled cylinders to verify purifier performance.

Q:  How can you guarantee that a customer does not back stream air or other contaminants into the cylinder and saturate 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 unique cylinder valve is designed to protect the purifier bed from inadvertent exposure to air or other materials. The cylinder valve is a unique 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. Additionally, the residual pressure valve closes at about 50 psig (3 barg), and guarantees a permanent positive pressure of gas in the cylinder that also prevents back contamination.

The unique 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 comprehensive quality control during manufacturing.

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:

  1. Air Products tests the performance of every purifier;
  2. The BIP® valve and the location of the purifier protect the purifier from inadvertent exposure to air; and
  3. 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 major 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:

  1. 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.

  2. Does the purifier manufacturer know the quality of the gas feeding the point-of-use purifier?

    No, 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 any point-of-use purifier. It is a complete integrated system available from one vendor.

Q:  Every gas company guarantees the product specifications. 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. Hundreds of thousands BIP® cylinders have been produced around the World, and each one of them has passed Quality Assurance testing.

Q:  What are the advantages of your purifier-in-a-cylinder concept versus my point-of-use purifiers?

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 eliminated - so are the labour costs for maintaining it.

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:  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. The particle specifications from BIP® cylinders are better than those from conventional cylinders.

Q:  Is this product suitable for ECD?

Yes – the BIP® purifier system very efficiently removes Halocarbons and other critical impurities making it perfect for ECD.