Gases

Gas Mixtures

  • Packaging Information and Breakseal Instructions

 

Frequently Asked Questions 

 

Frequently Asked Questions 

What is the pressure of a liquefied gas in a cylinder?

The pressure of a liquefied gas in a cylinder will be the vapor pressure of the liquid form of the gas at the temperature of the cylinder. Tables of vapor pressures of liquids may be found in the Handbook of Chemistry and Physics.

Are CIL's cylinders inspected and leak tested before filling?

All cylinders are inspected and leak tested before filling. However, it is the customer’s responsibility to inspect and weigh gas cylinders upon receipt to ensure that the product and/or packaging was not compromised during shipment.

When will a gas liquefy?

A gas will liquefy when the pressure exceeds the vapor pressure provided that the temperature does not exceed the critical temperature of the gas. The critical temperature (Tc) is defined as the temperature above which a substance cannot exist in the liquid state, regardless of the pressure.

Is it possible to synthesize ammonia?

It is impossible to synthesize ammonia (D2) or ammonia (D1) as a pure isotopic species or "isotopomer". The hydrogen atoms and (deuterium atoms) of ammonia rapidly exchange, resulting in scrambling, and a statistical mixture of ND3, NHD2, NH2D, and NH3.

What is the maximum pressure to which a deuterium hydride (DLM-194) can be packaged?

The maximum pressure to which deuterium hydride (DLM-194) may be packaged is 900 psi. Above this pressure the deuterium hydride will scramble, yielding a statistical mixture of H2, D2 and HD.

How do you calculate the approximate pressure in a cylinder at 20°C?

To calculate the approximate pressure in a cylinder at 20°C, use the equation below. [{(volume ordered x 14.7)/ (volume of cylinder)} - 14.7]x (293/273) = pressure (psi). Please note that this equation does not account for the nonideality of gases nor apply to gases that liquefy in the cylinder.

What are the CGA-580 valve and the CGA-350 valve used for?

For our 3L and 8L carbon steel cylinders, the CGA-580 valve is used for non-flammable gases, and the CGA-350 valve is used for flammable gases.

I ordered isotopically labeled gas in a small lecture bottle. Some of the documentation calls it a 460 mL bottle, some refer to a 0.44 L bottle. Shouldn’t these be the same number? Does one refer to the container and the other the contents?

The nominal approximate volume of the gas cylinders is 460 mL. In most cases, we also specify the actual gas volume. It can be confusing, but it is common practice to refer to the cylinder in terms of its capacity. These cylinders are sometimes referred to using their minimum volume, 440 mL or 27 in3. Of course, gas volumes vary with temperature and pressure. In practice, these parameters must be either specified or assumed for exact measurements. Historically, wide tolerances have been considered acceptable (e.g. 5%, 5% of 440 mL= 22 mL, 44 mL + 22 mL = 462 mL). Some of these conventions have been around since cylinder testing has been done hydrostatically. It was convenient to use one pound of water (at 20˚C occupies 455 mL). References to the container may not always use the same volume consistently, and the volume gas may differ from the volume of the cylinder.