API RP 11V2:2001(2008) pdf download

API RP 11V2:2001(2008) pdf download.Gas-lift Valve Performance Testing.
3.10 TEMPERATURE TAPS
3.10.1 General
Two temperature taps are requiret[ One temperature tap is required on the upstream side of the test section and another is required for the flow rate measurement device. An optional downstream teniperalure tap may be located on the downstream side of the test section.
3.10.2 Location
The upstream temperature tap should be located within the upstream side of the test section. The temperature tap used for flow rate measurement should be located as recommended by the manufacturer of the flow rate measurement device. There is no requirement for the location of the optional downstream temperature tap. however, it is recommended that if one is used. it be located within the downstream side of the test section.
3.10.3 OrientatIon
When located on a horizontal run, the temperature taps should be located above a horizontal plane extending through the centerline of the pipe.
3.11 TEMPERATURE MEASUREMENT
3.11.1 Accuracy
The devices used to measure gas temperature should not have an error exceeding ± 2°F (± 1.1 °C) of actual value.
3.11.2 Measurement Requirements
The gas temperature should be measured at the flow rate measurement device and on the upstrcani portion of the test section.
3.11.3 Temperature Reporting Requirements
A means should be provided to produce a hardcopy report of the temperatures measured at both the flow rate measurement device and at the upstream portion of the test section, This means should report temperatures within an accuracy of ± 2% of the temperature being measured.
3.12 EQUALIZING VALVES
The method of accomplishing the tests may require that the upstream and downstream pressures be equalized prior to testing. The equalizing valve is positioned between the upstream and downstream test section and allows the ability to bypass the test specimen.
3.13 GAS SUPPLY
Air or some other compressible gas should be used as the basic fluid in this test procedure. Vapors which may approach their condensation points at the vena contracta of the specimen are not acceptable. Care should be taken to avoid formation of liquids or solids in the gas supply during the test.
3.14 DOCUMENTATiON
The following information should be available as a means for demonstrating the compliance of the test apparatus with this recommendation. Data Form I is a convenient form that may be used for this purpose.
I. Schematic identifying the layout and location of items
I—S of 3.2 and signed by the person in charge of testing.
2. Detail drawing of the te.sL section showing:
a. distance from upstream test section to test specimen. h. distance from downstream Lest section to test Specimen.
c. number and size of receptacle inlet ports and annular flow area between valve and receptacle for wireline retrievable fixtures.
d. location and size of annular chamber around test specimen.
3. Type and capacity of throttling control valves.
4. Type and size of surge protection.
5. Type and accuracy of flow measurement device,
6. Type and accuracy of pressure measurement devices.
7. Tipe and accuracy of pressure recording hardcopy
device.
8. Type and accuracy of temperature measurement devices.
9. Type and accuracy of temperature recording hardcopy
device.
4 Gas-lift Valve Probe Test
4.1 INTRODUCTION
The purpose of the Gas-lift Valve Probe Test is to determine the relative “stiffness” of a gas-lift valve and to determine the masimum effective travel of the stem. When gas pressure is admitted to the tester, it must act on the full area of the valve bellows to lift the stem off the seat. When this pressure is increased, the stem lifts further from the seat. By using the Valve Probe Tester (see Figure 7), an accurate inca- sure of the stem travel versus pressure can be determined and the results tabulated and plotted. The valve probe tester shown in Figure 7 is an example and is not intended to restrict the many possible devices which may he used to accomplish the test.
When the pressure is plotted as the ordinate and the stein travel as the abscissa, a relatively straight line will be generated for the effective stem travel. The slope of this line is an indication of the “stillness” of the valve.