1、 ANSI/FCI 99-3-2012 AMERICAN NATIONAL STANDARD BACK PRESSURE REGULATOR CAPACITY Fluid Controls Institute, Inc. Sponsor: Fluid Controls Institute, Inc. 1300 Sumner Ave Cleveland, Ohio 44115-2851 iiANSI/FCI 99-3-2012 AMERICAN NATIONAL STANDARD Back Pressure Regulator Capacity Sponsor Fluid Controls In
2、stitute, Inc. AmericanNationalStandardAmerican National Standard implies a consensus of those substantially concerned with its scope and provisions. An American National Standard is intended as a guide to aid the manufacturer, the consumer, and the general public. The existence of an American Nation
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4、o obtain the latest editions. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of pub
5、lication. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute. Sponsored and published by: FLUID CONTROLS INSTITUTE, INC. 1300 Sumner Avenue Cleveland, OH 44115-2851 Phn: 216/241-7333 Fax: 216/241-
6、0105 E-Mail: fcifluidcontrolsinstitute.org URL: www.fluidcontrolsinstitute.org Copyright 2012 by Fluid Controls Institute, Inc. All Rights Reserved No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the p
7、ublisher. Suggestions for improvement of this standard will be welcome. They should be sent to the Fluid Controls Institute, Inc. Printed in the United States of America iiiivCONTENTS PAGE Foreword .v 1. Purpose .1 2. Scope 1 3. Definitions1 4. Test Method: Back Pressure Regulators . 2-3 Figures Fig
8、ure 1 2 Figure 2 2 Figure 3 3 Figure 4 4 Foreword (This foreword is included for information only and is not part of ANSI/FCI 99-3-2012, Back Pressure Regulator Capacity.) This voluntary standard has been developed by the Regulator Section of the Fluid Controls Institute, Inc to provide a test metho
9、dology for measuring and reporting the capacity of direct acting back pressure regulators. FCI recognizes the need to periodically review and update this standard. Suggestions for improvement should be forwarded to the Fluid Controls Institute, Inc., 1300 Sumner Avenue, Cleveland, Ohio 44115-2851. A
10、ll constructive suggestions for expansion and revision of this standard are welcome. The existence of a Fluid Controls Institute (FCI) standard does not in any respect preclude any member or non-member from manufacturing or selling products not conforming to this standard nor is the FCI responsible
11、for its use. Please go to the FCI web site for all of the latest technical articles and standards. vANSI/FCI 99-3-2012 AMERICAN NATIONAL STANDARD Back Pressure Regulator Capacity 1. PURPOSE To provide guidelines and procedures for measuring and reporting the capacity of direct acting back pressure r
12、egulators. 2. SCOPE This standard provides a method for establishing and reporting back pressure regulator capacities for use by manufacturers, users, specifiers and approval bodies in order to promote consistent presentation of back pressure regulator or surplusing valve capacities. This standard d
13、oes not apply to safety relief valves. 3. DEFINITIONS 3.1 Accuracy of Regulation. The deviation from the set point, expressed as a percentage or as a fixed unit, taken at the test conditions. 3.2 Controlled Variable. The variable which shall be monitored by the controlling process. The inlet pressur
14、e is the controlled variable for back pressure regulators. 3.3 Lockup (Dead End Shutoff). The deviation of the controlled variable from set point obtained at a no flow condition. 3.4 Cracking Pressure. The pressure required to produce the first detectable flow as the valve opens in response to incre
15、asing pressure. 3.5 Reseat Pressure. The pressure at which the valve produces no detectable flow as the valve closes in response to decreasing pressure. 3.6 Maximum Capacity. The flow rate at maximum travel to be used for safety or relief valve sizing. 3.4 Minimum Controllable Flow. The lowest flow
16、rate, at a given set point and temperature, at which a steady regulated condition of the controlled variable can be maintained. The minimum controllable flow is essentially zero for some regulators. Minimum controllable flow is used to determine turndown or rangeability. 3.5 Buildup. The deviation o
17、f the controlled variable measured as the flow varies from the minimum controllable flow to the rated capacity. Buildup is sometimes referred to as offset for pressure reducing valves. 3.6 Maximum Cv. Cvat maximum travel. 3.7 Rated Capacity. The rate of flow obtainable through a back pressure regula
18、tor, for specified inlet conditions and fluid, at a specified buildup or accuracy of regulation. 3.8 Rated Rangeability (Turndown). The rated capacity divided by the minimum controllable flow, usually expressed as a ratio. 3.9 Set Flow. The flow rate used to obtain the set point, typically 5 to 10%
19、of rated capacity. 3.10 Set Point. The regulator adjustment corresponding to the desired value of the controlled variable. 3.11 Spring Range. The useable pressure range for a spring. Data is assumed to be taken at the midpoint of a spring range unless otherwise noted. 1Supply Pressure Gage Secondary
20、 Pressure Primary Pressure Temperature SensorTemperature Test Regulator Sensor T1 P1 P2 T2 4. TEST METHOD. BACK PRESSURE REGULATORS 4.1. Suggested test set up and equipment is shown in Figure 1. Assure that all equipment has flow and pressure ratings equal to or greater than that expected in the tes
21、t. Accuracy of flow and pressure measurement shall be +/- 2% of actual. Accuracy of temperature measurement shall be +/- 1 C (2 F). 4.2. Install the Flow Meter in accordance with the manufacturers recommendations. Note that the Flow Meter can be located upstream or downstream of the test regulator a
22、nd test setup. 4.3. Use appropriate size conduits and fittings to connect the test unit in the test stand to prevent conduit flow restrictions from adversely influencing the test. 4.4. Pressure taps P1 and P2 to be located in the test setup as defined in Figure 2. 4.5. Assure that the test fluid is
23、properly filtered before it enters the test stand to protect the back pressure regulator under test and the instrumentation. 4.6. Close the supply valve and install the back pressure regulator to be tested in the test stand. 4.7. Adjust the back pressure regulators adjusting screw to its maximum set
24、ting. 4.8. Adjust the supply pressure of the fluid source to the desired setpoint that the back pressure regulator is to be set. 4.9. Open the supply valve and assure that there are no leaks in the setup. Verify that the primary pressure, P1, is correct. 4.10. Reduce the setting of the back pressure
25、 regulators adjustment screw until the Fluid Source Flowmeter Flowmeter (Alternate location)Discharge Reservoir Figure 1 Supply Valve 1 D 1 D 5 D 5 D 5 D D P1 P2Flow Inlet Outlet Test Regulator Figure 2 2back pressure regulator achieves its set flow. (See Figure 3) 4.11. Reduce the supply pressure 1
26、0% below the pressure where the flow stops. 4.12. Slowly increase the supply pressure and record the pressure in which the first detectable flow is noticed. This will be the cracking pressure. 4.13. Produce sufficient incremental flow rate steps by increasing the supply pressure to obtain a factual
27、representation of the back pressure regulators performance. Closely spaced data points will be required in the low flow region and high flow region for accurately determining characteristics where the valve first opens and when the valve approaches its maximum flow capacity. 4.14. Record the pressur
28、es P1 and P2, temperatures T1 and T2, and Flow Rate for each incremental increasing step in supply pressure. 4.15. Calculate the flow rate from the recorded data of flow, pressure, and temperature. 4.16. From the recorded and calculated data, plot a performance curve of the secondary pressure vs. fl
29、ow rate through the regulator. 4.17. Establish the desired accuracy of regulation and measure the rated capacity at that point. 4.18. Cracking pressure, offset, and maximum capacity can also be determined from the performance curve. (see Figure 3) 4.19. If desired, repeat steps 4.7 thru 4.16 for add
30、itional representative setpoints in the units regulating range from which a family of performance curves can be generated. 4.20. Optionally the rated and maximum coefficients (Cv) can be determined per ISA 75.01. 4.21. The rated capacity shall always be presented graphically or in tables. The fluid,
31、 setpoint, minimum flow and accuracy of regulation (or offset) shall always be specified with the capacity information. 3SEE FIGURE 4CONTROLLED VARIABLESYSTEM PRESSURE(PSIG)FLOW LIMIT (WIDE OPEN VALVE) RATED CAPACITYSETPOINTAND SET FLOW BUILDUP SETPOINT FLOW RATE (SCFM, GPM, #/HR) MAXIMUMCAPACITY Fi
32、gure 3. FlowSETPOINT ANDSET FLOW CRACKING PRESSURE RESEAT PRESSURE SETPOINT Figure 4. Cracking Pressure and Reseat 44FCI REGULATOR & CONTROL VALVE SECTION ADDITIONAL STANDARDS ANSI/FCI 70-2-2006, Control Valve Seat Leakage FCI 87-2-1990 (R 1998), Power Signal Standard for Spring Diaphragm Actuated C
33、ontrol Valves ANSI/FCI 91-1-2010, Standard for Qualifications of Control Valve Stem Seals FCI REGULATOR & CONTROL VALVE SECTION TECHNICAL BULLETINS Tech Sheet #CVR 401 Insulation Systems Used as External Treatment for Control Valve and Regulator Noise Tech Sheet #CVR 402 Fundamental Principles of Self-Operated Pressure Reducing Regultors Tech Sheet #CVR 403 Laminar Flow Valve Sizing Made Easy Tech Sheet #CVR 404 Simple Reference Guide: Differences Between Direct and Pilot- Operated Regulating Valves
