Air Liquide offers seven distinct product classes. One product class that offers product and specification customization is our Custom Class™ gas mixtures.

• These custom-engineered specialty gas mixtures can be produced to any level of certification you require, including dual-analyzed, dual-certified and single-certified.
• Air Liquide has a wide variety of components available for blending. We are also able to blend customer-supplied proprietary components.
• As you define the specialty gas or liquid mixture required, we can work with you to advise you on the type of traceability available.
• Air Liquide’s custom gas and liquid mixtures are available in a full line of refillable and transportable containers. Transportable cylinders are available for small volume applications or where container portability is necessary. Recommendations for use of steel, aluminum or other specialized cylinders are made in the interest of maximizing mixture stability and utility.
• Every analyzed Custom Class gas mixture is shipped with a Certificate of Accuracy. This customized document provides detailed product information, including special handling instructions and component information.

For more information about our custom specialty gas products, please contact us via email, request a quote or call our Solutions Center at 877.715.8651. Our highly trained representatives can provide expert assistance with technical issues as well as quick responses about quotes for custom products or grades not shown on this website.

Most SCOTT™ gas mixtures from Air Liquide America Specialty Gases can be NIST-traceable either directly or by weight. Direct NIST-traceability is achieved by laboratory analysis of your gas mixture on an instrument directly calibrated with gas reference material from NIST such as an SRM (Standard Reference Material) or NTRM (NIST-Traceable Reference Material). Using a GMIS (Gas Manufacturer's Intermediate Standard) to calibrate an instrument results in traceability but it is no longer directly traceable.

NIST-traceable by weight applies to process traceability rather than analytical traceability. In order to have process traceability, the blending method used for your gas mixture must also be directly calibrated with reference material from NIST. For example, if a gravimetric blending scale is calibrated with NIST Class 1 Weights or the older NIST Class S Weights, the resulting product is said to be "NIST-traceable by weight."

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

A flam-ox gas mixture is one that contains a flammable component such as methane and an oxidizer component such as air. Depending on the concentrations involved, there may be pressure restrictions placed on the mixture so that an explosion would be contained by the gas cylinder.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Air Liquide America Specialty Gases follows the guidelines of the Compressed Gas Association (CGA) when determining which valve to use for a particular gas mixture. The guidelines were developed primarily to prevent the intermingling of incompatible gases such as flammables and oxidizers or acids and bases. The valve outlet connection type is determined by the FTSC code for each component. This is a four-digit code consisting of four ratings: fire potential, toxicity, state of gas, and corrosiveness.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Air Liquide America Specialty Gases uses a wide variety of instrumentation and wet chemistry methods to analyze our gas mixtures. The method used is dependent on the components of the gas mixture, the concentrations of those components, and the blend and analytical requirements.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

An accuracy of ±2% means that the reported concentration is within 2% of the true concentration of the product.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Using the Ideal Gas Law (PV=nRT) as the starting point, it is fairly simple to calculate the cylinder content. To find the volume of gas available from a compressed gas cylinder, we apply the Ideal Gas Law (PV = nRT). In a high-pressure cylinder, the volume will be affected by the content's compressibility factor Z (PV = ZnRT). For example, a 30AL cylinder of pure helium may contain 134 cu. ft. of gas while the same cylinder of pure air may contain 144 cu. ft. under the same conditions. For these practical calculations, however, we assume ideal gas behavior for simplicity.

The Ideal Gas Law PV = nRT

Where:
P is pressure
V is volume
n is the number of moles
R is the gas constant
T is the absolute temperature

When the temperature is kept constant, we can derive the equation:
P (1) x V (1) = P (2) x V (2)

Where:
P (1) is the pressure of the compressed gas in the cylinder (psi)
V (1) is the internal volume of the cylinder, often referred to as water volume (liter)*
P (2) is the atmospheric pressure (1 atm - 14.7 psi)
V (2) is the volume of gas at pressure P (2) (liter).

Example: a 30AL sized cylinder is filled with nitrogen at 2000 psi. What is the gas volume of nitrogen from the cylinder?
P (1) is 2000 psi
V (1) is the internal volume of 30AL cylinder 29.5 liter*
P (2) is 14.7 psi
V (2) is the unknown volume of gas

Solving the equation above for V (2) gives:
V (2) = [p (1) x V (1)]/P (2) = (2000 psi x 29.5 liters)/14.7 psi = 4013 liters (approximately 140 cu. ft.)

* Click here to find the water volume of all Air Liquide high-pressure cylinders.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Air Liquide uses mole concentrations unless otherwise requested for specialty gas mixtures.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Blend tolerance is the difference between the blended concentration and the requested concentration. Blend accuracy is the difference between the measured value and the true value. It is calculated by taking the root mean square of the uncertainties.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Vapor pressure is the pressure exerted when a solid or liquid is in equilibrium with its own vapor at a particular temperature. Air Liquide typically uses the vapor pressure of each minor specialty gas component at 32°F (0°C) to calculate any vapor pressure restriction of the specialty gas mixture.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Example:
Given a 100 ppm (mole basis) gas mixture of Compound A in nitrogen, how much of Compound A will be contained in a 1 liter volume?

Key Assumptions:

• Temperature of sample is assumed to be at 21.1°C (70°F).
• Pressure of sample is assumed to be 1 atm just before injection. At around atmospheric pressure, gases behave in close to ideal manner.

Calculation:
Using the Ideal Gas Law (PV = nRT) for a temperature of 294.1°K (21.1°C), a pressure of 1 atm, and the gas constant R of 0.0821 liter x atm/mole x degree K, we find that 1 mole of ideal gas occupies 24.15 liters.

One liter of gas will then contain (1/24.15 ) moles. Since the concentration of Compound A is 100 ppm, the total number of moles of Compound A in 1 liter is (total # moles per liter) x (concentration of Compound A).

The concentration of 100 ppm (parts per million) is unit-less, and equals 100 mole-parts per 1,000,000 total moles = 0.000100 in decimal form; thus the amount of moles of Compound A in one liter of mixture is:

(1/24.15) moles per liter x 0.000100 = 0.000004 moles of Compound A per liter

In order to find the weight of Compound A, we need to know its molecular weight. For example, if Compound A is hydrogen sulfide, with a molecular weight of 34.08 gram/mole, we obtain the following concentration:

0.000004 moles per liter x 34.08 gram per mole = 0.000140 gram per liter or 0.140 milligram per liter

General Formula for Conversion of ppm (mole) to gram/liter for Gas Mixture:
(for temperature 21.1°C (70°F) and pressure 1 atm)

{Concentration (decimal form) x mole-weight (gram/mole)} of Comp. A/24.15 liter/mole = Concentration of Comp. A in g/l

Conversion of gram/liter to ppm (mole basis) for Gas Mixture:
(for temperature 21.1°C (70°F) and pressure 1 atm)

Concentration of Comp. A in gram or liter x 24.15 liter or mole/Mole-Weight of Comp. A in gram/mole = Concentration of Comp. A in decimal form

The concentration expressed in decimal form is unit-less. To find the concentration of Compound A in ppm, multiply the answer from equation above with 1,000,000. For example, a concentration of Compound A of 0.000100 (decimal form from equation above) would be 100 ppm, while a concentration of 0.010000 would be 10,000 ppm or 1%.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Air Liquide makes our Material Safety Data Sheets (MSDSs) available to customers via an online MSDS Library.

In order to maintain a safe, productive working environment and to ensure reliable, efficient use of compressed specialty gases, it is important that proper gas handling procedures be observed at all times. For these reasons, our MSDS Library provides comprehensive safety information specific to each Air Liquide compressed pure gas and gas mixture. To find safety information about a pure gas or gas mixture, enter the name of the specialty gas product into the search tool or the MSDS number for the gas you are requesting information.

The Air Liquide MSDS Library contains a detailed MSDS for every specialty gas product available in our catalog. For the benefit of workers and emergency personnel, we’ve outlined all necessary considerations and procedures related to our specialty gas products in an easy-to-read format. Each MSDS in the Air Liquide library contains information on the product’s composition and chemical properties, an overview of potential hazards, first-aid measures, fire fighting measures, accidental release measures, recommendations for handling and storage, toxicological information, ecological information, information on product disposal requirements and other important information.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Yes. Air Liquide America Specialty Gases manufactures custom pure gases and specialty gas mixtures to meet unique requirements. Air Liquide’s extensive purification capabilities and processes enable us to provide custom grades of pure gases and liquids for the engineer with specialized requirements. Furthermore, we are a one-stop source for supplying your new and unusual materials needs. Custom pure gases and specialty gas mixtures can be prepared to your specifications. Air Liquide’s leadtimes are the industry’s shortest.

For our pure gas products, Air Liquide is able to provide specification tables detailing total purity as well as guaranteed maximum concentrations of critical impurities. We have made every effort, based on input from our customers, to establish meaningful specifications for both purity assays and impurity specifications. Air Liquide pure gases are guaranteed to be free of critical contaminants that can cause instrument interference and chromatographic capillary column degradation. We achieve consistent high-purity through extensive gas cylinder preparation, dedication of gas cylinders by gas service, and statistical quality control.

Our knowledgeable representatives are trained to provide expert assistance with technical issues as well as quick responses about quotes for custom products or grades not shown on this website. Please contact us via email, request a quote, or call us at 877.715.8651 for more information about custom pure gases and liquid products.

Yes. Air Liquide America Specialty Gases offers pure gases in many cylinder sizes and volumes. You can choose from a vast selection of high-pressure, low-pressure and SCOTTY™ Transportable gas cylinders to contain your pure gases. High-pressure are returnable and refillable cylinders that hold larger volumes of pure gases. They are just right for applications requiring larger amounts of pure gases and where portability is not an issue. SCOTTY Transportable cylinders are nonrefillable cylinders and are perfect for applications that demand portability and smaller gas volumes.

If you cannot find a gas cylinder with the appropriate size on our website, we will create a product that meets your specifications. With over 100 years of specialty gas experience, Air Liquide can engineer the perfect cylinder size for your application. Don’t forget to visit our online MSDS Library for additional information on safe and proper handling of your specialty pure gas.

For more information, please contact us via email, request a quote or call our Solutions Center at 877.715.8651.

Pure materials or gas mixtures can exist in a liquid state or vapor state under the product’s recommended conditions.

Liquid phase refers to pure materials or specialty gas mixtures in which one or more components exist in a liquid state under the conditions (i.e., temperature) recommended for the product. Liquid phase materials can be stored in equilibrium with the gas phase in conventional specialty gas cylinders, or be forced to an all-liquid state in piston cylinders.

Gas phase refers to pure materials or specialty gas mixtures in which all main components remain in the vapor state within the conditions (i.e., temperature) recommended for the product.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Air Liquide America Specialty Gases analyzes all incoming raw materials to ensure only the highest quality products are used.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Impurities vary depending on the specialty gas and the product grade selected. Air Liquide America Specialty Gases lists the impurities in the description of each product.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Only SCOTTY 110 cylinders are refillable, all others are not.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

Air Liquide sells our EBS cylinders exclusively through Calgaz.

Yes. Air Liquide America Specialty Gases offers pure gases in many SCOTTY Transportable cylinders. Our SCOTTY Transportable gas cylinders come in a variety of convenient sizes that fit most applications. SCOTTY Transportable gas cylinders are a reliable and cost-effective alternative to returnable, high-pressure gas cylinders.

Features of the SCOTTY Transportable Gas Cylinders

• Calibration solutions for all types of applications.
• No cylinder demurrage or rental fees.
• Guaranteed accuracy and long-term stability.
• No two-way shipping charges.
• High quality SCOTTY accessory equipment available.
• Convenient “go anywhere” cylinder portability.
• Freedom to purchase only the amount of pure gas or gas mixture needed.

Pure gases in SCOTTY Transportable gas cylinders provide high-purity levels and accurate calibration. The proven accuracy and dependability of SCOTTY Transportable products enables precise measurement in the most demanding laboratory applications. What's more, SCOTTY Transportable products ensure a safer working environment in industrial hygiene and safety applications, as well as compliance with environmental monitoring regulations.

Regardless of your application, you can depend on Air Liquide America Specialty Gases for the most extensive offering of portable pure and mixed gases available anywhere. For information on the safe and proper handling of cylinder gases, be sure to visit our online MSDS Library.

For more information, please contact us via email or call our Solutions Center at 877.715.8651.

SCOTTY Transportable compressed gas cylinders are designed to be non-refillable and non-returnable. As specified by the U.S. Department of Transportation DOT 39 (49 CFR & 178.65) regulations, a disposable compressed gas cylinder is a container that cannot be filled and transported more than once. These non-refillable cylinders (NRC) are not hazardous when empty.

Benefits of the NRC Design

• Convenient compressed gas cylinder sizing
• Eliminates cylinder rental and two-way shipping charges
• Presents a cost-effective alternative to returnable gas cylinders

Guidelines for Compressed Gas Cylinder Disposal

The NRC design presents special disposal considerations. Air Liquide recommends the following guidelines for non-refillable compressed gas cylinder disposal:

• Dispose of contents in accordance with federal, state and local regulations.
• Attach an appropriate compressed gas regulator to the cylinder valve and allow any residual gas to vent slowly in an unconfined, well-ventilated area or exhaust hood
• Close the cylinder valve and remove regulator
• Open cylinder valve slowly and leave open
• Render the cylinder unusable by putting a hole in the cylinder
• Dispose of cylinder with solid waste (NOTE: DO NOT INCINERATE)

If you wish to dispose of refillable compressed gas cylinders, please return the cylinders to the supplier with any valve outlet plugs or caps secured and valve protection caps in place.

For additional information on compressed gas cylinder disposal, please contact us via email or call our Solutions Center at 877.715.8651.

Air Liquide America Specialty Gases carries a variety of gas cylinder stands for small cylinders.

SCOTT™ Model 62SB
This welded steel safety stand supports gas cylinders ranging in size from 3" to 4" in diameter. Designed for use with the SCOTTY 48 gas cylinder, it has an 11" (279.4 mm) base and a height of 4" (101.6 mm).

SCOTT Model 62SBS
Designed for slightly smaller gas cylinders ranging from 2.75" to 3.25" in diameter, this cylinder stand is intended for use with the following SCOTTY transportable cylinders: 110, 105, 35, 17, 14 and 11.

SCOTT Model 84S
Our floor-mounted gas cylinder stand adjusts to hold cylinders ranging in size from 6" (152.4 mm) to 9.25" (235 mm) in diameter. Its design allows the stand to hinge open and fit around the base of a gas cylinder thus eliminating any heavy lifting.

SCOTT Model 62SBM
Air Liquide also offers an inexpensive gas cylinder stand which is injection molded of chemical-resistant HPDE resin. This gas cylinder stand measures 7" (177.8 mm) in diameter at the base, 3" (76.2 mm) in height, and 3" (76.2 mm) across its cylinder opening. It is ideal for bench applications using the SCOTTY 14, 17 or 35 gas cylinders. A compression fit design makes it fast and easy to change cylinders.

SCOTT Model 30H
Last but not least, Air Liquide offers an aluminum cylinder stand designed specifically for lecture bottles. This gas cylinder stand has a 7.5" square base with four mounting holes and a 2" opening.

For more information, please contact us via email, request a quote, or call our Solutions Center at 877.715.8651.

In order to connect more than one cylinder to each side of an automatic changeover gas manifold, you will need to use header manifolds. Header manifolds are attached to the changeover manifold with flexible pigtails equipped with CGA fittings and check valves. Header manifolds are usually used in pairs – a left header and a right header. The left header has the outlet on the left end and the right header has the outlet on the right end. Header manifolds are typically available with two stations, but can be constructed to accommodate many more cylinders. Depending on the space available, they can be single rows or multiple rows. Each header station also comes with a station valve and a 24" flexible stainless steel pigtail equipped with a check valve and CGA fitting to attach to a cylinder.

Click here to learn more about SCOTT™ changeover manifolds. Or, contact us via email, request a quote, or call our Solutions Center at 877.715.8651.

The inlet connection of a header manifold is the CGA fitting that is appropriate for the gas in the cylinder.

Click here to learn more about SCOTT header manifolds. Or, contact us via email, request a quote, or call our Solutions Center at 877.715.8651.

Gas manifolds can easily be attached to special types of cylinder racks called process cylinder racks. Process cylinder racks differ from standard cylinder storage racks by having a cross beam above the tops of the cylinders. The manifolds are attached to the cross beam using the mounting brackets included with the manifolds.

Click here to learn more about SCOTT™ changeover manifolds. Or, contact us via email, request a quote, or call our Solutions Center at 877.715.8651.

Our SCOTT™ liquid changeover system combines a pressure-reducing regulator with high-purity diaphragm valves to create a compact gas delivery system that provides continuous gas flow on installations where dewars are used.

This system directs the flow of gas from two separate sources (dewars or banks) to your application. When one source empties, the changeover system automatically draws from the second source. The first source can then be changed without interruption to the outlet pressure.

The Model 8404L is available in brass or stainless steel. It also features a built-in gas saver circuit that eliminates waste by preventing the reserve supply's accumulated head gas pressure from being discharged to the atmosphere. During operation, the gas saver directs reserve supply pressure build-up to the primary supply where it is used. During shutdown periods, both supplies may be vented to the atmosphere. Adequate ventilation should be provided to safely remove or disperse the gaseous discharge.

Click here to learn more about the SCOTT Model 8404L. For more information, contact us via email, request a quote, or call our Solutions Center at 877.715.8651.

Single-stage gas pressure regulators reduce the cylinder pressure to the delivery pressure in one step, where a two-stage gas pressure regulator accomplishes the same thing with two stages of pressure reduction. This means that a single-stage regulator has to be adjusted to maintain a constant pressure as the gas in the cylinder is used, but a two-stage regulator does not.

Two-stage regulators are typically used when more stability of operation is required and are often used in specialty gas applications, like gas chromatography. On the other hand, if gas is being used for a short duration instrument calibration, a single-stage gas regulator with a wide accuracy envelope (supply pressure effect) but a comparatively flat droop should be chosen. This will eliminate the need to allow the gas to flow at a constant rate before the calibration can be done.

For more information, click here, contact us via email or call our Solutions Center at 877.715.8651.

Gas pressure regulators are used to regulate the gas pressure (pounds per square inch) and are not appropriate for measuring flowrate (liters per minute). Flowmeters, rotometers or mass flow controllers should be used to regulate gas flowrates.

Flowmeters measure liquid and gas flowrates for general plant and laboratory applications. Rotometers are special flowmeters named for the rotating float that functions as the indicating element. Mass flow controllers precisely measure, monitor and control gases on the basis of mass flow, eliminating the need for continuous monitoring and readjustment of gas pressures to provide a stable gas flow.

Below is available SCOTT™ Flow Measurement Equipment:

Model 28
High capacity variable area flowmeters offer a means of measuring gas at capacities higher than our other variable area flowmeters. Suitable for both plant and lab use.

Model 30
65MM flowmeter suitable for general plant and laboratory applications.

Model 31
150MM flowmeter suitable for research, laboratory and process gas flow requiring high accuracy and digital gas flowrate display.

Model 32
Low flow purge meters suitable for purging applications requiring visual inspection that gas is flowing to where needed.

Model 36A
Mass flow controllers with automatic control and digital flow rate display of gas flow for research, laboratory and process gases.

Model 36E
Mass flow secondary electronics designed to provide power, readout and control for Model 36A Mass Flow Controllers.

Click here for detailed equipment specifications for each of the above. Or, for more information, contact us via email or call our Solutions Center at 877.715.8651.

The deposit draw down program is an alternative to the standard daily rental payment method. The standard cylinder rental is $0.35 per day and is billed on a monthly basis. Many companies will issue multiple purchase orders – one for the purchase of the gas and one for the ongoing cylinder rental. With deposit draw down, a deposit (based on the cylinder size) is paid to Air Liquide on the same purchase order as the gas. When using the deposit draw down option, Air Liquide America Specialty Gases deducts the daily cylinder rental at a 10% discount, until the cylinder is returned. If the cylinder is returned before the deposit is depleted, a credit is issued for the balance.

For more information, contact us via email or call our Solutions Center at 877.715.8651.

Air Liquide America Specialty Gases will only sell our compressed gas cylinders to the US Government, customers outside North America, or customers exporting cylinders outside of the United States.

For more information, contact us via email or call our Solutions Center at 877.715.8651.

Air Liquide America Specialty Gases offers pure gases and gas mixtures in a wide variety of steel and aluminum cylinders.

Click here to view available our standard cylinder sizes. Custom sizes are also available. For more information, contact us via email or call our Solutions Center at 877.715.8651.