Liquefied Mixtures

CAC Gas offer liquefied gas mixtures in a range of different cylinders including constant pressure (CPC), collapsible liquid vessel (CLV) and standard gas cylinders fitted with dip tube valves.

Liquefied gas mixtures are used where the application demands calibration with ‘heavy’ or longer-chain hydrocarbons. Liquid mixtures have the advantage of closely matching the product being analysed, while also offering increased efficiency by allowing an increased number of calibrations with the same cylinder, when compared to a gaseous mixture.

Traditionally, liquefied gas mixtures were supplied in regular high-pressure cylinders with dual port dip tube (DP/DT) valves. Maintaining the mixture in liquid phase is achieved by it being kept under pressure by an overpressure gas, usually helium. While this is the most cost-effective solution, CAC GAS offers two other options in additions to dip tube cylinders.

Collapsible Liquid Vessel Cylinders
The CLV uses a collapsible bag inside a standard cylinder with conventional dual port dup tube valve to hold the liquid. There is a physical barrier between the liquid (which is inside the bag) and the overpressure which is inside the cylinder. The new, patented technology keeps the LPG / NGLs in a single liquid phase which provides a stable liquid composition over the lifetime of the cylinder.

Advantages of CLV cylinders:

• Cost. CLV cylinders require lower upfront cost and no servicing costs.
• Volume. The CLV can hold a high volume of liquid, reducing the mixtures cost per litre in addition to reduced handling and procurement costs through needing to order them less frequently.
• Physical size. CLV cylinders can hold large volumes of gas in a cylinder of manageable size.

Constant Pressure Cylinders
The CP cylinder is designed with internal pistons and seals. The cylinder is pressurised with an inert gas supply, before being turned around and filled slowly from the opposite end. By letting the gas push against the piston, slowly venting the pre-charge gas, the sample is taken at full line pressure from start to finish. While the cylinder is being emptied, full pressure is being maintained and the gas composition is not being altered as a result.

Advantages of CP cylinders:

• History. The CP cylinder is a historically proven technology. The CP cylinders have been around a very long time, many operators are familiar with using them and the track record of performance is indisputable.
• Composition. The CP cylinder can accommodate a much wider variety of compositions.
• The mixers. CP cylinders come with a variety of mixers which can be critical for maintaining homogeneity of the compositions.

CAC GAS Asia offers specialty gas products for gas detection, process gas analysis, environmental monitoring and laboratory gas analysis applications in Singapore. CAC GAS Asia brings years of practical knowledge and skills in understanding customer requirements and providing solutions that exceed customer expectations.