Orifice metering is one of the most commonly used metering technology in the gas production and transmission industry. This is due to the low installation and maintenance cost, and the low uncertainty which can be achieved using these meters.

Another significant advantage orifice meters have over most other technologies is the ability to use the meters without having them proved or calibrated (Note that there is a requirement to calibrate the instrumentation measuring pressure, differential pressure and temperature, but not to flow prove the meters themselves). This feature is achieved by precisely defining the geometry of the meter, so that each meter reacts similarly to the flow of gas. This is referred to as dynamic similarity.

The CPA 50E Flow Conditioner consists of a steel plate with a central circular hole and two rings of circular holes in concentric circles around the central hole. The spacing and design of the flow conditioner has been developed to produce a fully developed profile downstream of the conditioner. The holes account for about 50% of the area of the plate, and are sized such that the velocity profile a short distance downstream will be the same as the fully developed profile. The thickness of the plate also eliminates swirl which may exist upstream of the meter.

The design is patented and cannot be used without permission.