1、 MSS SP-108-2015 Resilient-Seated Cast Iron Eccentric Plug Valves Standard Practice Developed and Approved by the Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. 127 Park Street, NE Vienna, Virginia 22180-4602 Phone: (703) 281-6613 Fax: (703) 281-6671 E-mail: standards
2、msshq.org www.msshq.org MSS STANDARD PRACTICE SP-108i This MSS Standard Practice was developed under the consensus of the MSS Technical Committee 112 and the MSS Coordinating Committee. The content of this Standard Practice is the resulting efforts of competent and experienced volunteers to provide
3、an effective, clear, and non-exclusive standard that will benefit the industry as a whole. This MSS Standard Practice describes minimal requirements and is intended as a basis for common practice by the manufacturer, the user, and the general public. The existence of an MSS Standard Practice does no
4、t in itself preclude the manufacture, sale, or use of products not conforming to the Standard Practice. Mandatory conformance to this Standard Practice is established only by reference in other documents such as a code, specification, sales contract, or public law, as applicable. MSS has no power, n
5、or does it undertake, to enforce or certify compliance with this document. Any certification or other statement of compliance with the requirements of this Standard Practice shall not be attributable to MSS and is solely the responsibility of the certifier or maker of the statement. “Unless indicate
6、d otherwise within this MSS Standard Practice, other standards documents referred to herein are identified by the date of issue that was applicable to this Standard Practice at the date of approval of this MSS Standard Practice (see Annex A). This Standard Practice shall remain silent on the validit
7、y of those other standards of prior or subsequent dates of issue even though applicable provisions may not have changed.” By publication of this Standard Practice, no position is taken with respect to the validity of any potential claim(s) or of any patent rights in connection therewith. MSS shall n
8、ot be held responsible for identifying any patent rights. Users are expressly advised that determination of patent rights and the risk of infringement of such rights are entirely their responsibility. In this Standard Practice all text, notes, annexes, tables, figures, and references are construed t
9、o be essential to the understanding of the message of the standard, and are considered normative unless indicated as “supplemental“. All appendices, if included, that appear in this document are construed as “supplemental“. Note that “supplemental” information does not include mandatory requirements
10、. U.S. customary units in this Standard Practice are the standard; (SI) metric units are for reference only. Substantive changes in this 2015 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 materia
11、l flagged with that in the previous edition. Non-toleranced dimensions in this Standard Practice are nominal unless otherwise specified. Any excerpts of this Standard Practice may be quoted with permission. Credit lines should read Extracted from MSS SP-108-2015 with permission of the publisher, Man
12、ufacturers Standardization Society of the Valves and Fittings Industry. Reproduction and/or electronic transmission or dissemination is prohibited under copyright convention unless written permission is granted by the Manufacturers Standardization Society of the Valve and Fittings Industry Inc. All
13、rights reserved. Originally Published: June 1991 Current Edition Approved: April 2015 Current Edition Published: July 2015 MSS is a registered trademark of Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Copyright , 2015 by Manufacturers Standardization Society of the
14、Valve and Fittings Industry, Inc. Printed in U.S.A. MSS STANDARD PRACTICE SP-108ii TABLE OF CONTENTS SECTION PAGE 1 SCOPE 1 2 DEFINITIONS 1 3 PRESSURE AND TEMPERATURE RATINGS . 1 4 END CONNECTIONS . 2 5 DESIGN 2 6 MATERIALS 3 7 ACTUATION . 3 8 FASTENERS 3 9 WORKMANSHIP . 3 10 TESTING 4 11 MARKING 5
15、12 INSTALLATION 5 13 PREPARATION FOR SHIPMENT 5 14 STORAGE 5 TABLE 1 Face-to-Face Dimensions for Flanged Valves 2 2 Minimum Duration of Shell and Seat Tests, All Classes 4 3 Number of Cycles for Valve Sizes 4 FIGURE 1 Eccentric Plug Valve Nomenclature and Plug Position 6 2 Eccentric Plug Valve Seat
16、Marking and Flow Direction Nomenclature . 7 3 Recommended Installation Positions for Suspended Solid Service 8 ANNEX A Referenced Standards and Applicable Dates . 9 MSS STANDARD PRACTICE SP-1081 1. SCOPE This Standard Practice covers quarter-turn eccentric cast iron plug valves having flanged, threa
17、ded, mechanical joint, or grooved end connections. This Standard Practice is intended for resilient-seated valves with a circular, rectangular, or other geometric seat configuration, having no visible evidence of leakage. The size range covered is NPS 3 through NPS 72 (DN 80 through DN 1800). Typica
18、l applications are sewage, sludge, waste water, and water service. The manufacturer should be consulted for other applications. Conditions of water hammer, hydraulic pulsation, and excessive operating noise are results of the system design rather than valve design and require special design and cons
19、truction considerations. 2. DEFINITIONS 2.1 Eccentric The center line of the plug journal is offset from the center line of the seat. (See Figure 1 for typical geometry.) Shut-off is accomplished by rotating the eccentrically mounted plug into the body seat. 2.2 Resilient Seat A seat design whereby
20、the shut off of flow is accomplished by compressing a resilient material against a corrosion resistant surface. 2.3 Direct Pressure Pressure exerting force on the plug from opposite the body seat end (see Figure 2). 2.4 Reverse Pressure Pressure exerting force on the plug from the body seat end (see
21、 Figure 2). 2.5 Bi-directional Capable of sealing direct and reverse pressure. 2.6 CWP “Cold Working Pressure“ The maximum pressure at which a valve is allowed to be used at ambient temperature. 2.7 Port Area The minimum cross sectional area within the valve perpendicular to the flow, expressed as a
22、 percentage of the internal cross sectional area of the connecting pipe. The connecting pipe is the size listed as “standard“ in ASME B36.10M. 2.8 NPS Indicates “Nominal Pipe Size” (U.S customary). A standard size identification number is not necessarily an actual dimension. The European designation
23、 equivalent to NPS is called DN (diametre nominal/nominal diameter) in which sizes are based on (SI) metric units. Guidelines for (SI) metric data may be found in MSS SP-86. 2.9 System Pressure Maximum specified operating pressure for the application. 2.10 Quarter-Turn Nominal 90 rotation of the plu
24、g. 2.11 Other Definitions Other definitions may be found in MSS SP-96. 3. PRESSURE AND TEMPERATURE RATINGS 3.1 Valves NPS 3 through NPS 12 (DN 80 through DN 300) shall be rated for 175 psig CWP, minimum. 3.2 Valves NPS 14 through NPS 72 (DN 350 through DN 1800) shall be rated for 150 psig, CWP, mini
25、mum. 3.3 The maximum shut off pressure may be less than the rated CWP but shall not be less than purchaser specified system pressure. 3.4 Valves manufactured to this Standard Practice are limited to applications with service temperatures from 33 F through 180 F (0.56 C through 82.2 C). RESILIENT-SEA
26、TED CAST IRON ECCENTRIC PLUG VALVES MSS STANDARD PRACTICE SP-1082 4. END CONNECTIONS 4.1 Flanged Ends 4.1.1 Flanges shall be compatible with ASME B16.1, Class 125 flanges, or AWWA C110/A21.10. 4.1.2 Flanges shall be faced in accordance with ASME B16.1 and MSS SP-6. 4.1.3 Flange diameter, bolt circle
27、, and bolt holes shall be to ASME B16.1, Class 125. 4.1.4 Flange bolt holes that are threaded shall be tapped per ASME B1.1 coarse thread series, Class 2B. 4.1.5 Face-to-face dimensions for flanged end valves shall be per Table 1. TABLE 1 Face-to-Face Dimensions for Flanged Valves NPS Face-to-Face D
28、imensions(a)(Inches) Short Body Long Body 3 8 4 9 6 1012 8 111210 13 12 14 14 17 16 173424 18 211230 20 231236 24 30 42 30 371251 36 52 60 42 72 48 84 54 96 60 96 105 66 96 115 72 96 125 Note: (a) Tolerance for valves NPS 10 and smaller is 1/8 inch. Tolerance for valves NPS 12 and larger is 3/16 inc
29、h. 4.2 Threaded Ends Threaded ends shall have tapered pipe threads manufactured to the dimensions of ASME B1.20.1. 4.3 Mechanical Joint Ends Mechanical joint ends shall be manufactured to the dimensions of AWWA C111/A21.11; or, for bodies made of ductile iron, mechanical joint ends may be manufactur
30、ed to the dimensions of AWWA C153/A21.53. 4.4 Grooved Ends Grooved ends shall be manufactured to the dimensions of AWWA C606. 5. DESIGN 5.1 General Eccentric plug valves are to be the quarter-turn type. The eccentric plug is to rotate clockwise (CW) to close and counter-clockwise (CCW) to open. Duri
31、ng opening, the plug face lifts from the body seat as the plug is rotated open. There shall be external visible indication of the plug position. In the full open position, the sealing surface of the plug is rotated out of the flow passageway (see Figure 1). 5.2 Valve Bodies The valve body wall thick
32、ness is to be designed with a minimum safety factor of five (5) based on ultimate tensile strength. 5.3 Seats The valve seating surface shall consist of a resilient sealing material which mates with a corrosion resistant material. 5.4 Bearings Bearings are to be permanently self-lubricated having su
33、rfaces that resist galling. The bearing material is to be non-corrosive based on the specified service conditions. The compressive stress is not to exceed 1/5 of the ultimate compressive strength of the bearing material. All valves are to contain an upper and lower plug stem bearing. MSS STANDARD PR
34、ACTICE SP-1083 Acceptable materials include, but are not limited to, the following: a) 18-8 Stainless Steel b) Oil Impregnated bronze c) Fluoropolymer d) NYLON 11 5.5 Stem Seals The seals are to be accessible for visible inspection, and either adjustment or replacement without disassembly of the val
35、ve. All seal retaining components made of steel, e.g. snap rings, fasteners, etc. are to be plated or coated with zinc, epoxy, or other corrosion resistant material. 5.6 Bi-directional Rating The valve design shall be capable of shut-off in both directions at the full CWP rating. The valve design ma
36、y require special adjustments for reverse direction applications. The purchaser, therefore, shall inform the manufacturer of their differential shutoff pressure requirements for reverse direction applications. For reverse direction application, the valve shall be tested per Section 10.1.2.2 of this
37、Standard Practice. 6. MATERIALS 6.1 The body, plug, and bonnet shall be made from gray iron conforming to ASTM A126 Class B, ASTM A48/A48M Class 40, or ductile iron conforming to ASTM A536 with a minimum yield strength of 45,000 psi. 6.2 The resilient seating material shall be selected based on serv
38、ice conditions specified by the purchaser. 6.3 Corrosion resistant seat materials may include but not be limited to the following: a) 95% Nickel Alloy Weld Material b) Thermosetting Epoxy per MSS SP-98 c) Fusion Bonded NYLON 11 d) Stainless Steel AISI 300-series 7. ACTUATION 7.1 Manual actuators use
39、d with these valves must be self-locking and have provisions to prevent unwanted plug movement during normal operating conditions. 7.2 Many factors such as flow media, operating pressure, fluid velocities and location in the pipe line affect the operation of the valve. These conditions must be consi
40、dered when selecting the actuator. See MSS SP-91 for guidelines in selecting manual actuators. 7.3 Externally adjustable end of travel stops are to be provided in both the open and closed position. 8. FASTENERS 8.1 Carbon Steel 8.1.1 Carbon steel bolting materials shall meet the physical strength re
41、quirements of ASTM A307, and may have either regular square or hexagonal heads, with dimensions conforming to ASME B18.2.1. 8.1.2 Carbon steel bolts, studs, and nuts shall be: (1) Zinc coated as per ASTM A153/A153M or ASTM B633, or (2) Rust proofed by some other process disclosed to and accepted by
42、the purchaser. 8.2 Stainless Steel 8.2.1 Stainless steel bolts shall comply with ASTM F593, Groups 1, 2, 5 or ASTM A193/A193M, Grades B6, B8, B8M. 8.2.2 Stainless steel nuts shall comply with ASTM F594, Groups 1, 2, 5 or ASTM A194/A194M, Grades 6, 8, 8M. 9. WORKMANSHIP All valve parts shall be inter
43、changeable with other valves of the same size, model, and CWP rating manufactured by the same company. All castings shall be clean, sound, and have no defects that could impair their service. MSS STANDARD PRACTICE SP-1084 10. TESTING 10.1 Production Testing 10.1.1 Shell Test With the plug in the ope
44、n position and the valve ends sealed, each assembled valve shall be subjected to a hydrostatic pressure of one and one half (1.5) times the cold working pressure. The duration of the test is specified in Table 2. No visible leakage or visible permanent deformation is permitted. Stem seal leakage dur
45、ing the hydrostatic shell test shall not be cause for rejection. 10.1.2 Seat Test After the hydrostatic shell test, each valve is to be subjected to a hydrostatic seat test pressure at least equal to the purchaser specified seat test pressure or system pressure for the minimum duration in Table 2. T
46、ABLE 2 Minimum Duration of Shell and Seat Tests, All Classes NPS Shell Test (Seconds) Seat Test (Seconds) 12 and Smaller 14 24 Larger than 24 30 60 180 15 30 60 10.1.2.1 Direct Pressure Unless otherwise specified by the purchaser, the seat test shall be direct pressure. No visible leakage is permitt
47、ed at the seat, stem seal, or the pressure containing joint. 10.1.2.2 Reverse Pressure For purchaser specified reverse pressure applications, the seat test shall be in the reverse direction. The valve qualifies for reverse pressure use if there is no visible seat leakage during the seat test and no
48、visible stem seal leakage during the hydrostatic shell test. If there was stem seal leakage during the shell test, then the stem seal must be retested at the purchaser specified seat test pressure or system pressure for the minimum duration in Table 2. 10.1.2.3 Bi-directional Pressure The reverse pr
49、essure test in Section 10.1.2.2 qualifies the valve for bi-directional use provided there is no stem seal leakage during the hydrostatic shell test in Section 10.1.1. 10.2 Proof of Design If required by the purchaser, the manufacturer shall furnish certified copies covering proof of design tests. 10.2.1 Structural Test of the Plug One valve of each size shall be tested. The valve is to be tested in the closed position. A pressure of two (2) times the cold working pressure is to be applied to one side of the plug, and then the other. No brea
