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The Market for Positive Displacement Flowmeters

High Accuracy a Major Factor

Accuracy and reliability continue to be the strongest driving forces behind the flowmeter market. Positive displacement meters are highly accurate because they actually separate the fluid into compartments and count the number of times this is done. There is no need for the inferential method that occurs with meters that correlate flow with velocity, or use the differential pressure method to measure flow. PD meters are widely used for billing applications because they are both accurate and reliable. Both the degree of accuracy and reliability vary with the manufacturer and the type of PD meter.

Sales of Positive Displacement flowmeters

Positive displacement sales are being helped by new applications in oil & gas, cryogenics, ultra pure water processing, and other applications.  Suppliers who support the aerospace industry are reporting an uptick in government spending for the military as well as for civilian and government aircraft flight applications.

Some relatively new developments focus on improved methods to increase the precision with which components are manufactured.  For example, improved coordinate measuring machines make it possible to create more perfectly round pistons and other components.  And as is the case with turbine flowmeters, improved bearing technology is making ball bearings more reliable and less prone to fail.

For information on available market studies, please see http://www.flowpd.com

Installed Base a Major Factor

One major growth factor for positive displacement flowmeters is the large installed base of positive displacement flowmeters worldwide.  Because they were introduced more than 100 years before new-technology meters, positive displacement flowmeters have had much more time to penetrate the markets in Europe, North America, and Asia.

Installed base is a relevant growth factor because often when ordering flowmeters, especially for replacement purposes, users often replace like with like.  The investment in a flowmeter technology is more than just the cost of the meter itself.  It also includes the time and money invested in training people how to install and use the meter.  In addition, some companies stock spare parts or even spare meters for replacement purposes.  As a result, when companies consider switching from one flowmeter technology to another, there is more than just the purchase price to consider.  The large installed base of positive displacement flowmeters worldwide will continue to be a source of orders for new and replacement meters in the future.

Regulatory Approvals Favor PD Meters

Positive displacement meters are specified by approval bodies for use in custody transfer for utility measurement in residential, commercial, and industrial applications.  These organizations include the American Water Works Association (AWWA) and the International Standards Organization (ISO) in Europe .  These approvals have been in place for many years.  The AWWA has approvals for both nutating disc and oscillating piston meters.  Magnetic flowmeters are starting to make inroads in this area, however.

Despite their advantages, PD flowmeters face competition from new-technology meters.  In the area of oil flow measurement, PD meters face a stiff challenge from Coriolis meters.  Because oil is a high-value product, end-users are more willing to pay the higher prices of Coriolis meters to measure its flow.  PD meters are widely used to measure the flow of hydrocarbon products, especially downstream of refineries at custody transfer points and for fiscal and utility measurements.

Utility Applications Dominate

While new-technology flowmeters are making inroads into traditional meters in many areas and applications, this is less true for positive displacement flowmeters for gas applications. Close to 80 percent of revenues from PD meters for gas flow measurement derive from utility applications, where PD meters are highly entrenched. This includes PD meters for commercial and industrial applications, where utility companies use them to measure the amount of gas consumed by restaurants, office buildings, and other establishments. While there has been a shift from diaphragm to rotary meters PD for these applications, these applications have seen no strong shift away from PD meters. Turbine meters are used for high speed flow utility applications, however.

The use of PD diaphragm and rotary meters for gas applications is somewhat like the use of mutating disc and piston PD meters for utility and billing applications in the water industry. PD meters, along with single-jet and multi-jet turbines are still the dominant meter for utility measurement of water flows, especially in residential and smaller commercial applications. However, some new-technology flowmeters such as magnetic and Coriolis are beginning to gain approvals from industry associations for use in utility measurement of water. It is likely, then, that new-technology meters will eventually be used on a more widespread basis for utility gas measurement.

There are two main types of PD meters used for gas utility billing— diaphragm meters and rotary meters. Rotary meters are replacing diaphragm meters in many cases. Rotary meters are smaller and lighter than diaphragm meters. This replacement is occurring for other gas applications as well. Elster (www.elster.com) is the dominant supplier in this market.

For information on positive displacement suppliers and manufacturers, and other flowmeters companies, select Companies under Discover More at the home page, or simply click here: http://www.legendsofflow.com.

Oval gear meters are quite popular for oil applications, especially for downstream oil distribution involving custody transfer. Here they compete with Coriolis meters, which are gaining market share in downstream oil measurement. 

Positive-displacement meters do best in line sizes between 1.5 inches and 10 inches. It is unusual to find PD meters in line sizes above 10 inches. One strength of PD meters is high accuracy.  Positive-displacement meters actually capture the fluid in compartments of known quantity and measure how often they do this. They are also very good at measuring fluid with low flowrates.  Downsides of positive-displacement meters include pressure drop and mechanical moving parts.


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