If a meter is flow calibrated, log files should be collected at various flow rates during the flow calibration. The manufactures should supply software that can be used for the collection of these logs. These logs can be used as a “baseline” to compare with future data. This is extremely valuable as a diagnostic tool […]
Read More →Category: Orifice-Meter Measurement
Calibration of the UM
The initial calibration of the UM is normally the dry calibration. Dry calibration insures that the proper calibration parameters were entered into the meter electronics and all components are operating correctly. Dry calibration entails blinding both ends of the meter and filling the meter body with a known gas (normally nitrogen). Using a known gas, […]
Read More →Orifice Well Test
Often it is necessary to determine an approximate flow quantity from a well head or field separator vent to the atmosphere for test purposes. The use of a “well head tester” has been a common practice since the early days of the oil and gas industry. See Figure 3-14. An orifice is installed between a […]
Read More →Orifice Flow Rate
The following example illustrates a calculation of flow rate through an orifice. Example 3-2 — Calculate an approximate flow rate for the orifice using appropriate terms from Eq 3-4. Given Data: Line Size, D = 6.065 in. Orifice Size, d = 3.500 in. Flange Taps Flowing Temperature = 70°F Flowing Pressure = 90 psia Differential […]
Read More →Orifice Sizing
A simple calculation is often needed to properly size an orifice plate for new or changing flow rates through existing meter tubes. The procedure uses an existing or assumed flow quantity, a desired differential pressure at a specific static pressure, an estimated flowing temperature, and a determined or assumed specific gravity. The Key orifice coefficient […]
Read More →Meter Tubes
The term “meter tube” shall mean the straight upstream pipe ahead of the orifice fitting of the same internal diameter as the orifice fitting (length UL on Fig. 3-9) and the similar downstream pipe (length DL on Fig. 3-9) following the orifice. The sections of pipe to which the orifice flanges are attached or the […]
Read More →Meter Tubes
The term “meter tube” shall mean the straight upstream pipe ahead of the orifice fitting of the same internal diameter as the orifice fitting (length UL on Fig. 3-9) and the similar downstream pipe (length DL on Fig. 3-9) following the orifice.
Read More →Orifice Plates
The minimum, maximum, and recommended thicknesses of orifice plates for various pipe sizes are given in Figure 3-6. Also shown in this figure are maximum allowable differential pressures for stainless steel plates of the recommended thickness at a maximum temperature of 150 degrees F. The thickness of the orifice plate at the orifice edge (e) […]
Read More →Dual-Chamber Orifice Fitting
This fitting allows the removal and inspection of an orifice plate while the line remains under pressure. It allows the orifice plate holder and orifice plate to be raised into the upper cavity of the fitting by the use of a crank handle. A valve is then closed to separate the upper cavity from the […]
Read More →Single Chamber Orifice Fitting
This fitting also requires that the line be shut down and depressured in order to inspect or change the orifice plate. However, this fitting does not require breaking apart the flanges. Instead, the bolts are loosened on the cover plate and the cover plate removed. The orifice plate holder and orifice plate are then removed […]
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