1、 ANSI/FCI 70-3-2004 AMERICAN NATIONAL STANDARD REGULATOR SEAT LEAKAGE Fluid Controls Institute, Inc. Sponsor: Fluid Controls Institute, Inc. 1300 Sumner Ave Cleveland, Ohio 44115-2851 ii ANSI/FCI 70-3-2004 AMERICAN NATIONAL STANDARD Regulator Seat Leakage Sponsor Fluid Controls Institute, Inc. iii C
2、ONTENTS PAGE Foreword iv 1. Purpose 1 2. Scope and Limitations .1 3. Definitions1 4. Leakage Specifications and Classes 1 5. Test Procedures. 2 6. References3 Tables Table 1 2 Table 2 3 iv Foreword (This foreword is included for information only and is not part of ANSI/FCI 70-3-2004, Regulator Seat
3、Leakage.) This voluntary standard has been compiled and issued in the public interest. It is intended to eliminate present misunderstandings and to assist and guide those people involved in the specification, use or manufacture of regulators. The standard was developed by the FCI Regulator Section i
4、n 2001. 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 for its use. FCI recognizes the need to periodically review and update this s
5、tandard. Suggestions for improvement should be forwarded to the Fluid Controls Institute, Inc., 1300 Sumner Avenue, Cleveland, Ohio 44115-2851. All constructive suggestions for expansion and revision of this standard are welcome. 1 ANSI/FCI 70-3-2004 AMERICAN NATIONAL STANDARD Regulator Seat Leakage
6、 1. PURPOSE 1.1 This standard establishes a series of seat leakage classes for regulators and defines the test procedures. 2. SCOPE & LIMITATIONS 2.1 This standard applies to pilot operated and direct acting pressure reducing, pressure relieving (back pressure), differential pressure and temperature
7、 regulators. 2.2 Selection of a leakage class is not restricted as to regulator design, but acceptable values for various commercially available designs are suggested for each class under Section 4. 2.3 The standard cannot be used as a basis for predicting leakage at conditions other than those spec
8、ified. 2.4 This standard is similar to FCI 70-2. 2.5 This standard does not apply to pressure regulators as defined in the following standards: ANSI Z21.18/CSA 6.3 ANSI Z21.80/CSA 6.22 ANSI Z21.78/CSA 6.20 3. DEFINITIONS 3.1 Regulator. A self-contained valve operated by the flowing fluid or by the p
9、rocess energy from a directly connected sensing device. 3.2 Cv- An experimentally determined valve sizing coefficient. (Ref. ISA S75.01, ISA S75.02 and FCI Standard 84-1). 3.3 Maximum Capacity The flow rate at maximum travel generally used for safety or relief valve sizing. 3.4 Maximum Cv. Maximum C
10、vis Cvat maximum capacity calculated per ISA S75.01 generally used for safety relief valve sizing. For pilot-operated regulators maximum Cvincludes the Cvof the pilot. 3.5 Maximum Travel. The regulator travel in the fully open position at the maximum design travel corresponding to maximum capacity.
11、3.6 Seat Leakage. The quantity of test fluid passing through an assembled regulator in the closed position under the test conditions as defined. 4. LEAKAGE SPECIFICATIONS & CLASSES 4.1 The maximum allowable seat leakage as specified for each class shall not exceed the seat leakage in Table 1 using t
12、he test procedure as defined in Section 5. For Classes II through VII each and every regulator shall be tested. The Cvof the pilot must be included. 4.2 Leakage Classes 4.2.1 CLASS I. A modification of any Class II, III or IV regulator where the design intent is the same as the basic class, but by a
13、greement between user and supplier, no test is required. 4.2.2 CLASS II. This class establishes the maximum permissible leakage generally associated with commercial double-seat regulators with metal-to-metal seats. 4.2.3 CLASS III. This class establishes the maximum permissible leakage generally ass
14、ociated with Class II (4.2.2), but with a higher degree of seat and seal tightness. 4.2.4 CLASS IV. This class establishes the maximum permissible leakage generally associated with commercial unbalanced single-seat regulators with metal-to-metal seats. 4.2.5 CLASS VI. This class establishes the maxi
15、mum permissible seat leakage generally associated with resilient seating regulators either balanced or unbalanced with “O” rings or similar gapless seals. 4.2.6 CLASS VII. This class establishes the maximum permissible seat leakage generally associated with Class VI (4.2.5), but with test performed
16、at the maximum operating differential pressure. 2 TABLE 1 Leakage Class Maximum Seat Leakage Class I (See 4.2.1) See Paragraph 4.2.1 Class II (See 4.2.2) 0.5% of maximum CvClass III (See 4.2.3) 0.1% of maximum CvClass IV (See 4.2.4) 0.01% of maximum CvClass VI (See 4.2.5) Leakage per Table 2 as expr
17、essed in ml per minute versus seat diameter Class VII (See 4.2.6) Leakage per Table 2 as expressed in ml per minute versus seat diameter 5. TEST PROCEDURES Warning: Provisions should be made to avoid overpressuring of measuring devices resulting from inadvertent opening of the valve plug. 5.1 Test m
18、edium shall be clean air or nitrogen gas at 10-51C (50-125F). 5.2 Test Pressure or Temperature 5.2.1 Reducing Regulator 5.2.1.1 Reducing Regulator Class II-VI The pressure of the test medium shall be 3-4 bar (45-60 psig) or the maximum operating differential pressure, whichever is less. 5.2.1.2 Redu
19、cing Regulator Class VII The pressure of the test medium shall be the maximum operating differential pressure or 3.5 bar (50 psig), whichever is greater. For regulators with normal operating differentials greater than 17 bar (250 psi), the pressure of the test medium shall be 17 bar (250 psig) unles
20、s otherwise agreed to with the customer. 5.2.2 Back Pressure Regulator 5.2.2.1 Back Pressure Regulator Class II-VI The pressure of the test medium shall be 90-98% of the pressure defined by the first detectable flow or 3-4 bar (45 to 60 psig), whichever is less. 5.2.2.2 Back Pressure Regulator Class
21、 VII The pressure of the test medium shall be 95-98% of the pressure defined by the first detectable flow. 5.2.3 Temperature Regulator 5.2.3.1 Temperature Regulator Class I-VI The test temperature must be within 10% of the set temperature (F) or the unit may be tested by applying air pressure (or va
22、cuum) to the actuator to simulate a closed valve before the fill medium is added. 5.2.3.2 Temperature Regulator Class VII The test temperature must be within 5% of the set temperature (F). 5.3 Leakage flow data shall be accurate to +/- 10% of reading. Pressure and temperature data shall be accurate
23、to +/- 1% of reading. 5.4 The test fluid shall be applied to the normal or specified regulator body inlet. The regulator body outlet shall be connected to a suitable measuring device. 5.5 The regulator shall be adjusted to meet the operating conditions specified. The full normal closing thrust as ap
24、plied by air pressure, a spring, or other means shall then be applied. No allowance or adjustment shall be made to compensate for any increase in seat load obtained when the test differential is less than the maximum regulator operating differential pressure. 5.6 The leakage rate thus obtained can t
25、hen be compared to the calculated values for Classes II, III and IV in Table 1 or the values in Table 2 for Classes VI and VII. 3 TABLE 2 Nominal Seat Diameter Millimeters (Inches) Standard ml per Minute * Bubbles per Minute* 25 (1)* 0.15 1* 38 (1.5) 0.30 2 51 (2) 0.45 3 64 (2.5) 0.60 4 76 (3) 0.90
26、6 102 (4) 1.70 11 152 (6) 4.00 27 203 (8) 6.75 45 250 (10) 11.1 - 300 (12) 16.0 -350 (14) 21.6 -400 (16) 28.4 -*Bubbles per minute as tabulated are a suggested alternative based on a suitable calibrated measuring device in this case a 6 mm (0.24 inch) O.D. x 1 mm (0.04 inch) wall tube submerged in w
27、ater to a depth of from 3 to 6 mm (0.12 to 0.24 inch). The tube end shall be cut square and smooth with no chamfers or burrs and the tube axis shall be perpendicular to the surface of the water. Other apparatus may be constructed and the number of bubbles per minute may differ from those shown as lo
28、ng as they correctly indicate the flow in ml per minute. *If the valve seat diameter differs by more than 2 mm (0.08 inch) from one of the values listed, the leakage rate may be obtained by interpolation assuming that the leakage rate varies as the square of the seat diameter. *Standard milliliters
29、based on 15.6 C (60 F) and 1 bara (14.73 psia). 6. REFERENCES 6.1 Fluid Controls Institute Standard: FCI 70-2, Control Valve Seat Leakage. 6.2 Fluid Controls Institute, Regulator Terminology, FCI 86-2. 6.3 Instrument Society of America, Control Valve Capacity Test Procedure, ANSI/ISA S75.02-1998. 6.4 Instrument Society of America, Flow Equations for Sizing Control Valves, ISA 75.01.01-2002. 6.5 CEN European Committee for Standardization, Gas Pressure Regulators for Inlet Pressures up to 100 bar, rEN 334.
