Saudi Aramco has installed two V-Cone flow meters for its Udhailiyah and Shedgum gas plants in eastern Saudi Arabia.
To handle wet gas, a 6-in. meter was purchased for the Udhailiyah plant. For the Shedgum plant and to handle gas with condensate from the Khuff gas field, a 10-in. meter was installed.
McCrometer, Hemet, Calif., supplied both meters.
Differential measurements
The V-Cone flow meter provides differential pressure (Dp) flow metering with an accuracy of up to
It can measure even the most disturbed flow without the upstream or downstream straight-piping requirements of other meters, says McCrometer, making it suitable for tight-space applications and retrofits.
The meter can be sized for line diameters of 0.5 in. to larger than 120 in.
McCrometer says the direction of flow is into the small end of the cone to the large end (Fig. 1). The high-pressure measurement is first taken upstream of the cone, and the low-pressure measurement is then taken from the center of the upstream end of the cone.
A differential-pressure transmitter provides a signal of the differential between the two measurements to the customer's flow computer or other instrumentation.
The diameter of the cone (the "beta") is calculated based on the flow conditions of a particular application. The cone may appear (Fig. 1) to be a large obstruction but the area (annular opening) between the outside of the cone and the pipe wall is actually the same as the opening in an orifice plate with the same beta.
In practice, the V-Cone is typically calibrated at a much lower differential pressure for the same flow conditions than either an orifice plate or venturi meter, says McCrometer. Therefore, the permanent pressure loss created by the V-Cone is slightly higher than the venturi but much lower than an orifice plate for the same flow conditions.
Measurement is in only one direction. The cone shape conditions the incoming flow profile and mixes the flow which, says the manufacturer, gives the V-Cone its unique benefits of good flow turndown, accuracy, repeatability, and requiring minimal upstream straight runs of pipe.
