How the BIP Cylinder Technology Works
The BIP Technology is a complete purification system contained within a cylinder. It consists of a purifier bed and a patented valve. Gas filling the cylinder bypasses the purifier. It is then purified as it is withdrawn through the purifier bed.
Purifier Bed
The purifier bed removes oxygen, moisture, hydrocarbons, halocarbons, carbon monoxide, and carbon dioxide from inert gases. Exposed only to our own high-quality gas, the bed is sealed inside the cylinder in an inert atmosphere at high pressure.
Our specifications and guarantees are based on empirical data from controlled studies. We verify the performance of every purifier during manufacturing, and check purifiers after they are installed in cylinders. We do not have to regenerate the purifiers every time we refill a BIP cylinder. An ongoing quality control program tracks the actual performance of the cylinders according to the number of refill cycles. Because we know the purifier's properties, the actual concentrations of the impurities in our gases, and the number of times a cylinder is refilled during its lifetime, we can control and guarantee the lifetime of the purifiers to a tight specification.
Patented Valve
The patented valve has two features that protect the internal purifier from accidental contamination by air or a user's process line:
- A check valve protects both the purifier and the cylinder interior from any gas present at the valve outlet at a pressure higher than cylinder pressure. It also prevents Air Products from filling the cylinder through the purifier.
- The check valve also functions as a residual pressure valve. It closes when the cylinder pressure drops to about 50 psig (3 barg), maintaining a positive pressure in the cylinder at all times. Thus, the cylinder cannot be drained and the interior accidentally exposed to atmospheric O2 and H2O if the cylinder valve should be left open. The check/residual pressure valve is a redundant system protecting the purifier and cylinder.
The BIP cylinder valve also incorporates an additional gas flow path that is accessed by a secondary or bypass valve. This flow path connects the interior of the cylinder with the valve outlet, bypassing the flow path to the purifier, thus allowing the BIP cylinders to be filled around the purifier and not through it.
T-Purge and Regulator Assembly
To reduce the risk of air contamination associated with cylinder changeout, Air Products specially designed the gas supply system for the BIP cylinders. The integrated system consists of an analytical two-stage regulator and an upstream T-purge (or "block-and-bleed") valve assembly consisting of a vent valve on the tee'd leg and an in-line shutoff valve. This system connects the cylinder valve outlet with an Air Products regulator. The shutoff valve is just upstream of the regulator and protects it from exposure to air during cylinder changeout. The vent valve is between the shutoff valve and the cylinder valve outlet. With this T-purge assembly, the section of gas line between the regulator and the cylinder can be purged with clean carrier gas before the regulator is opened to feed gas to the instrument.
Under normal circumstances, when a cylinder is being changed, it takes over four hours to purge the air from the lines. With the T-purge assembly, the nominal purity of the carrier gas is obtained after about six minutes.
Please note, the T-Purge valve block is available as a separate item from Airgas.
Safety Features
The vent valve is equipped with an internal flow restrictor to protect the user from being exposed to the full cylinder pressure when operating the vent valve.
To ensure point of use purity, you need to connect the system to the cylinder and instrument and follow these purging instructions:
BIP Cylinder Automatic Changeover Panels
The high-purity BIP cylinder automatic changeover panel is specifically designed for use with Air Products' new BIP gas cylinders. The panel ensures an uninterrupted supply of gas while maintaining guaranteed purity specifications of less than 10 parts per billion (ppb) oxygen and less than 20 ppb moisture. Available from Airgas.
For more information, see our Data Sheet
(You will need the free Adobe Acrobat Reader to view the PDF file.)
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