1、 MSS SP-42-2013 Corrosion-Resistant Gate, Globe, Angle, and Check Valves with Flanged and Butt Weld Ends (Classes 150, 300, each should be used independently of the other. Combining or converting values between the two systems may result in non-conformance with this Standard Practice. Substantive ch
2、anges in this 2013 edition are “flagged” by parallel bars as shown on the margins of this paragraph. The specific detail of the change may be determined by comparing the material flagged with that in the previous edition. Non-toleranced dimensions in this Standard Practice are nominal unless otherwi
3、se specified. Excerpts of this Standard Practice may be quoted with permission. Credit lines should read Extracted from MSS SP-42-2013 with permission of the publisher, Manufacturers Standardization Society of the Valve and Fittings Industry. Reproduction and/or electronic transmission or disseminat
4、ion is prohibited under copyright convention unless written permission is granted by the Manufacturers Standardization Society of the Valve and Fittings Industry Inc. All rights reserved. Originally Published: October 1949 Current Edition Approved: October 2012 (Updated March 2013) Current Edition P
5、ublished: May 2013 MSS is a registered trademark of Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Copyright , 2013 by Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Printed in U.S.A. i MSS STANDARD PRACTICE SP-42 TABLE OF CONTENTS SECT
6、ION PAGE 1 SCOPE . 1 2 STANDARD UNITS . 1 3 MATERIALS . 1 4 DESIGN . 2 5 PRESSURE-TEMPERATURE RATINGS 7 6 WORKMANSHIP . 8 7 TESTS 8 8 MARKING 8 9 PAINTING . 8 TABLE 1 Minimum Diameter of Stems . 9 2 Stuffing Box Dimensions . 10 FIGURE A1 Gate Valves . 11 A2 Globe Valves . 11 A3 Y-Pattern Globe Valve
7、 11 A4 Angle Valve . 11 A5 Lift Check Valve, Bolted Cover Plate . 12 A6 Swing Check Valve, Bolted Cover Plate . 12 A7 Y-Pattern Swing Check Valve, Threaded Cover Plate 12 A8 Y-Pattern Swing Check Valve, Bolted Cover Plate 12 ANNEX A Valve Types Figures A1 through A8 11 B Referenced Standards and App
8、licable Dates . 13 ii MSS STANDARD PRACTICE SP-42 CORROSION-RESISTANT GATE, GLOBE, ANGLE, AND CHECK VALVES WITH FLANGED AND BUTT WELD ENDS (CLASSES 150, 300, however, replacement under pressure is not recommended. 4.14 Glands Glands shall be bolted type, solid, or two piece design. The two-piece des
9、ign shall be self-aligning consisting of a gland proper and a separate gland flange. The gland proper shall have a shoulder on its outer end to prevent complete entry of the gland into the stuffing box. The gland flange shall have holes (not slots) for two gland bolts minimum. 4.15 Gland Bolting Stu
10、ds, stud bolts, hinge bolts, or headed bolts through drilled or with slotted holes in the packing box flange may be used. In all cases gland bolting shall be securely held in place and shall provide adequate adjustment for progressive compression of packing material. 4.16 Stuffing Box, Packing and L
11、antern Ring 4.16.1 The stuffing box bore for the corresponding stem diameter shall be as listed in Table 2. The nominal stuffing box depth shall be at least equivalent to 5 rings of square packing. The stuffing box shall have a finish Ra of 175in. (4.5m) or smoother. 4.16.2 The nominal packing size
12、shall be as specified in Table 2. 4.16.3 When specified in the purchase order, a lantern ring for Class 300 and Class 600 valves shall be furnished. The lantern ring shall have two holes spaced 180 degrees apart on each end for its removal. These holes shall be either through-holes for use with a ho
13、ok, or threaded holes of the 1/8-coarse-thread series (No. 5-40 UNC), as specified in ASME B1.1, or M3-0.5 threads as specified in ASME B1.13M. If a lantern ring is furnished, the stuffing box shall be tapped opposite the center of the installed lantern ring and shall be fitted with a threaded solid
14、 round or hex-head plug greater than or equal to NPS 1/4. The plug shall be in accordance with the requirements of ASME B16.11. The stuffing box shall have a boss or wall thickness to accommodate the plug as required by ASME B16.34 for auxiliary connections. 5 MSS STANDARD PRACTICE SP-42 When a lant
15、ern ring is furnished, the stuffing box depth shall be at least equivalent to that of a minimum of three uncompressed rings of packing above the lantern ring and three uncompressed rings of packing below the lantern ring, plus the length of the lantern ring. 4.17 Gaskets Body-bonnet gaskets may be e
16、ither full faced or extending to the inside of the bonnet bolts or retained in recess in the bonnet flange of the body. 4.18 Bolting 4.18.1 Bonnet and yoke bolting shall be headed bolts or continuously threaded stud bolts with heavy semi-finished hexagonal nuts conforming to the requirements of ASME
17、 B18.2.2 or ASME B18.2.4.6M. When headed bolts are used they shall be limited to Class 150 in sizes NPS 8 (DN 200) and smaller, and Class 300 in sizes NPS 6 (DN 150) and smaller. Bonnet bolting for valves NPS 212(DN 65) and smaller may utilize cap screws. 4.18.2 The body-bonnet joint shall be secure
18、d by a minimum of 4 bolts, and the cross sectional area shall meet Section 6.4 of ASME B16.34 requirements for bolted bonnet or cover joints. 4.18.3 Gland bolting shall be headed bolts, hinged eyebolts, or studs with hexagonal nuts. 4.18.4 Bolting 1 inch (M24) and smaller shall have coarse (UNC) thr
19、eads or the most nearly corresponding metric threads. Bolting larger than 1 inch (M24) shall be 8-thread series (8-UN) or the most nearly corresponding metric threads. Bolt threads shall be Class 2A and nut threads Class 2B in accordance with ASME B1.1 or Class 6H/6g for metric threads under ASME B1
20、.13M. Studs used for gland bolting shall be secured with a Class 5 interference-fit in accordance with ASME B1.12. 4.19 Operation 4.19.1 Unless specified in the purchase order, the valve shall be operated directly by a handwheel. 4.19.2 If chainwheel operation is required, the type of chainwheel and
21、 chain required shall be specified in the purchase order. 4.19.3 If gear operation is required, the purchase order shall specify the type of gears and their arrangement, the design maximum differential pressure across the valve, and the maximum force (rim-pull) to operate valve. The latter shall be
22、the force exerted on the outer circumference of the handwheel. 4.19.4 If power operation is required, the type of power, the power unit, and the design maximum differential pressure across the valve shall be specified in the purchase order. 4.20 Auxiliary Connections When specified in the purchase o
23、rder, auxiliary connections to the valve body or bonnet, such as drains, bypass and/or test taps, shall be furnished to ASME B16.34 requirements. When required for NPS 2 (DN 50) or larger valves, auxiliary connections shall be identified by type, size, and location designation (see Section 4.21 for
24、bypass location) in the purchase order. 4.21 Bypass 4.21.1 Unless specified in the purchase order, a bypass shall not be furnished. 4.21.2 A bypass that is furnished shall be of the valve external type and of a size that is specified in ASME B16.34. The bypass shall be located on the side of the val
25、ve connecting either the A-B or the E-F locations shown in ASME B16.34. Unless specified in the purchase order, the bypass valve stem shall have the same general orientation as the primary valve stem. 4.21.3 Unless otherwise specified in the purchase order, the bypass valve shall be an outside-screw
26、-and-yoke rising stem globe valve with a flanged or welded bonnet. The bypass valve, including piping, shall be of a Pressure Class at least equal to that of the primary valve, and shall conform to the requirements of ASME B16.34. 6 MSS STANDARD PRACTICE SP-42 4.21.4 Bypass piping shall conform to t
27、he requirements in Section 4.20. 5. PRESSURE-TEMPERATURE RATINGS 5.1 General Flanged end and butt weld end valves covered by this Standard Practice shall be designated as Class 150, 300, or 600. The pressure temperature ratings shall be in accordance with the ASME B16.34, Table 2 Standard Class, (in
28、cluding applicable notes), for the appropriate material and pressure class. Except as provided in Section 5.5, ratings for all valves are the maximum allowable working pressures, expressed as gauge pressure, at the temperatures shown. For intermediate temperatures, linear interpolation is permitted.
29、 For an installed valve to merit the pressure-temperature ratings above, the bolting and gaskets for the end flanges must be in accordance with ASME B16.5. 5.2 The temperatures listed are the material temperatures of the pressure retaining structure. In view of the various environments in which pipi
30、ng components may be installed (for example, insulated or uninsulated, heated or cooled externally) in establishing pressure ratings, it is assumed that the material temperature of the pressure retaining structure is the temperature of the contained fluid. Use of a temperature other than that of the
31、 contained fluid is the responsibility of the user and subject to the requirements of any applicable code. 5.3 Temperature Effects (Application) Some considerations on the effect of temperature, in application, are given below. Additional guidance can be found in ASME B16.5, as related to line flang
32、e joints. 5.3.1 Low Temperature For an applicable pressure class and material shown in ASME B16.34, Table 1, the pressure rating for service at any temperature below -20 F (-29 C) shall be no greater than the pressure rating shown in the ASME B16.34, Table 2 for -20 F to 100 F (-29 C to 38 C). 5.3.2
33、 Cryogenic Temperature Gate, globe, and angle valves designed for cryogenic cold box service shall include extended body/bonnet extensions per MSS SP-134 requirements. 5.3.3 Fluid Thermal Expansion Under certain conditions, some double seated valve designs are capable of sealing simultaneously again
34、st pressure differential from the bonnet section to the adjacent pipe in both directions. A circumstance in which the bonnet section is filled with liquid and subjected to an increase in temperature can result in a buildup of pressure in the bonnet section. An example is an isolation valve in a cryo
35、genic fluid system having the liquefied gas trapped in the bonnet cavity of the closed valve. If the cavity pressure is not relieved by a suitable auxiliary means, pressure increase will result during subsequent warming of the cryogenic fluid. Where such a condition is possible, it is the responsibi
36、lity of the purchaser to provide, or require to be provided, the means in design and/or installation, or procedure in operation, by which to assure that the pressure in the valve will not exceed what is allowed by this Standard Practice for the attained temperature. 5.4 Guidance for the Use of Flang
37、ed Valve Ratings Application of flanged end valves at either high or low temperatures or in a service subject to rapid fluid temperature variations entails some risk of flanged joint leakage. Guidance, which is intended to minimize these risks, is provided in ASME B16.5. Precautions regarding the bo
38、lting of steel flanged end valves to cast iron flanges are given in ASME B16.5. 5.5 Variance Except as provided for below, the rating is the maximum allowable working pressure for the corresponding temperature. 5.5.1 Safety Valve, Relief Valve or Rupture Disc Operation Under conditions of safety val
39、ve, relief valve or rupture disc operations, the pressure may exceed the rated pressure for a valve furnished under this Standard Practice by no more than 10 percent (10%) of that defined by the pressure-temperature rating. Such conditions are necessarily of limited duration. 7 MSS STANDARD PRACTICE
40、 SP-42 Operating excursions in excess of the aforementioned are the sole responsibility of the user and are subject to the requirements of applicable codes and regulations. 5.5.2 Other Variances Subjecting valves to operating variances (transients) in excess of the valve ratings is solely the respon
41、sibility of the user and is subject to the requirements of applicable codes and regulations. 5.5.3 System Hydrostatic Tests If valves conforming to this Standard Practice are subjected to hydrostatic pressure testing of systems with the valve in the closed position at pressures greater than the 100
42、F (38 C) rating, such testing will be the responsibility of the user. In the open position, valves installed in a piping system may be subjected to system tests at conditions not to exceed the hydrostatic shell test of Section 7, provided the user has determined that there are no functional limitati
43、ons; for example, restrictions on actuating devices or special materials of construction. 6. WORKMANSHIP Valve parts shall be designed, and manufacturing tolerances set, so as to provide interchangeability of like parts in the product of any one manufacturer, between units of the same size and type;
44、 excepting the individual fit of the wedge or disc into the body seat. 7. TESTS All pressure tests shall be performed on completed valves prior to shipment from the manufacturers facility, in accordance with MSS SP-61. 8. MARKING Marking shall conform to MSS SP-25 and ASME B16.34 where applicable. T
45、rim material symbols need not be marked on identification plate unless the valve is trimmed with materials having basic chemistry different from the valve body. 9. PAINTING Unless otherwise specified in the purchase order, valves shall not be painted or provided with other protective coating. Howeve
46、r, exterior parts not in contact with the corrosive media and regularly furnished from material other than stainless steel may be coated to prevent atmospheric corrosion. 8 MSS STANDARD PRACTICE SP-42 TABLE 1 Minimum Diameter of Stems Dimensions are in inches and millimeters. Class Valve Size 150 30
47、0 600 (NPS) Stem Diameter Stem Diameter Stem Diameter in. mm in. mm in. mm 1/2 0.43 10.9 0.50 12.7 0.50 12.7 3/4 0.43 10.9 0.50 12.7 0.50 12.7 1 0.50 12.7 0.62 15.7 0.62 15.7 1 0.50 12.7 0.62 15.7 0.62 15.7 1 0.56 14.2 0.75 19.0 0.75 19.0 2 0.62 15.7 0.75 19.0 0.75 19.0 2 0.62 15.7 0.75 19.0 0.87 22
48、.0 3 0.75 19.0 0.87 22.0 1.00 25.4 4 0.87 22.0 1.00 25.4 1.12 28.4 6 1.00 25.4 1.25 31.7 1.50 38.1 8 1.12 28.4 1.37 34.7 1.62 41.1 10 1.25 31.7 1.50 38.1 1.87 47.4 12 1.37 34.7 1.62 41.1 2.00 50.8 14 1.62 41.1 1.75 44.4 2.25 57.1 16 1.75 44.4 1.87 47.4 2.37 60.1 18 1.87 47.4 2.00 50.8 2.50 63.5 20 2
49、.00 50.8 2.12 53.8 2.75 69.8 24 2.25 57.1 2.50 63.5 3.00 76.2 NOTE: The minimum listed stem diameters apply to the stem in the packing area. 9 MSS STANDARD PRACTICE SP-42 TABLE 2 Stuffing Box Dimensions Dimensions are in inches and millimeters. Nominal Stem Diameter Nominal Stuffing Box Bore Nominal Packing Size Nominal Stuffing Box Depth in. mm in. mm in. mm in. mm 0.44 11.2 0.75 19.1 5/32 4.0 0.78 19.8 0.50 12.7 0.88 22.4 3/16 4.8 0.94 23.9 0.56 14.2 0.94 23.9 3/16 4.8 0.94 23.9 0.62 15.7 1.12 28.4 1/4 6.4 1.25 31.8 0.69 17.5 1.19 30.2 1/4 6.4 1.25 31.8 0.75 19.1 1.
