1、I - . . MIL-V-24517 48 7499906 046346b 7 MILITARY SPECIFICATION I VALVE, STEAM PRESSURE REDUCING, QUIET DESIGN -_I_ I This specification is approved for use by the Naval Sea Systems Command and is available for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 This speci
2、fication covers quiet design, self-contained steam pressure reducing valves for submarines. 2. APPLICABLE DOCUMENTS 2.1 The following documents of the issue in effect on date of invitation for bids or request for proposal, form a part of the specification to the extent specified herein. SPECIFICATIO
3、NS MILITARY MIL-V-3 - Valves, Fittings, and Flanges (Except for Systems MIL-R-196 - Repair Parts for Internai Combustion Engines, Packaging of. MIL-S-901 - Shock Tests, H.I. (High-Impact): Shipboard Machinery, Equipment and Systems, Requirements for. MIL-R-17131 - Rods, Welding, Surfacing. MIL-G-210
4、32 - Gaskets, Metallic-Asbestos, Spiral Wound. Indicated Herein); Packaging of. STANDARDS MILITARY MIL-STD-167-1 - Mechanical Vibrations of Shipboard Equipment (Type I - MIL-STD-271 - Nondestructive Testing Requirements for Metals. MIL-STD-278 - Fabrication Welding and Inspection; and Casting MIL-ST
5、D-740 - Airborne and Structureborne Noise Measurements and Environmental and Type II - Internally Excited). Inspection and Repair for Machinery, Piping and Pressure Vessels in Ships of the United States Navy. Acceptance Criteria of Shipboard Equipment. (Copies of specifications, standards, drawings,
6、 and publications required by suppliers in connection with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer.) the extent-i- Unless otherwise indicated, the issue in effect on the date of invitation for bids or request for proposa
7、l shall apply. 2.2 Other ublications The following documents form a part of this specification to NATIONAL BUREAU OF STANDARDS Handbook 828 - Screw-Thread Standards for Federal Services. (Application for copies should be addressed to the Superintendent of Documents, Govern- ment Printing Office, Was
8、hington, D.C. 20402.) AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) B1.12 - Class 5 Interference - Fit Thread. B16.5 - Steel Pipe Flanges and Flanged Fittings. B18 - Bolts and Nuts. (Application for copies should be addressed to the American National Standards Institute, 1430 Broadway, New York, N.Y.
9、 10018.) FSC 4820 MIL-V-24517 (SHIPS) 28 April 1975 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-i - MIL-V-24CL7 48 m 777770b 04b34b7 O m Internal trim (main valve and pilot), plug, seat ring, guide posts and bushings Cylinder liner and piston Gas
10、kets NIL-V-245 17 (SHIPS) AMERICAN SOCIETY FOR TESTING AND MATERIAL (ASTM) A105-73 - Forgings, Carbon Steel for Piping Components. A193-74 - Alloy-Steel and Stainless Steel Bolting Materials for High A194-73 - Carbon and Alloy Steel Nuts for Bolts for High-pressure and A216-74 - Carbon, Steel Castin
11、gs Suitable for Fusion Welding for High- A306-66 - Carbon Steel Bars Subject To Mechanical Property Requirements. Temperature Service. High-Temperature Service. Temperature Service. (Application for copies should be addressed to the American Society for Testing and (Technical society and technical a
12、ssociation specifications and standards are generally Materials, 1916 Race Street, Philladelphia, Pa. 19103.) available for reference from libraries. They are also distributed among technical groups and using Federal agencies.) 3. REQUIREMENTS 3.1 Qualification. Valves furnished under this specifica
13、tion shall be products which are qualified for listing on the applicable qualified products list at the time set for opening of bids (see 4.3 and 6.3). Downstream-sdi shall be sensed by a spring-loaded diaphragm to position a pilot valve which utilizes inlet steam pressure to position the main valve
14、 plug via an operating piston. listed in table I shall be corrosion-resistant, suitable for the intended pressures and temperatures, and selected to prevent galling, seizing, or excessive wear on operating parts, Clearances shall prevent interferences due to the thermal expansion. 3.2 Valve descri t
15、ion Valves shall be a self-contained, internal pilot operated type. 3.3 Materials. Materials shall be as specified in table I. Materials for parts not Table I - List of materials. _ Stellite (see note) Hardened 400 series stainless steel 400 series stainless steel with surface hardness of 500 Brinel
16、l minimum (44OOC shall be used only when approved) MIL-G-21032, class B 2 Bolting Name of part I Materialc A-286 Inconel 600 Tungsten tool steel ASTM A193, grade 87 ASTM A194, grade ZH Body, bonnet, and bottom cover I ASTM A105 ASTM A216, grade WCB ASTM A306, grade 60 Diaphragm I Nickel-copper alloy
17、 I 300 series stainless steel I Nickel-chrome alloy Springs I Inconel X-750 -_ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-V-24517 YB m 777970b OYb34b 2 i NIL-V-24 517 (SHIPS ) 3.4 Desiqn and construction, 3.4.1 Desi n conce t. Valves will be
18、 operated, maintained, and repaired onboard Naval ships dadasize simplicity , maintainability , ruggedness, and reliability. Design shall permit access for adjustment and repair when working from either side of the valve and without requiring removal of the valve body from the line. 3.4.2 Maintainab
19、ilit . Internal parts shall permit easy disassembly and reassembly with standard tools and shall prevent, as far as practical, the incorrect reassembly of parts. Positioning and alinement of all parts in assembly shall employ positive means so that correct reassembly is repeatedly assured. physicall
20、y interchangeable or reversible unless such parts are also interchangeable or reversible with regard to function, performance and strength. within the time limits specified: In no case shall parts for a given valve be 3.4.2.1 Valve design shall permit accomplishment of the following maintenance acti
21、ons Action Time allowed Renew pilot valve 1/2 hour assembly trim Renew main valve trim 3/4 hour Remove, clean, and 2-1/2 hours replace quiet flow regulating element 3.4.3 Interchangeability. Valve design shall permit interchangeability without individual modification of like parts between all valves
22、. identity and shall be replaceable from stock or the manufacturer on a non-selective and random basis. Parts having the same manufacturers part number shall be directly inter- changeable with each other with respect to installation (physical) and performance (function). Physically interchangeable a
23、ssemblies, components, and parts are those which are capable of being readily installed, removed, or replaced without alteration, misalinement, or damage to parts being installed or to adjoining parts. No fabrication operations such as cutting, filing, drilling, reaming, hammering, bending, prying,
24、or forcing shall be required. This is not intended to preclude the use of special tools, fixtures, and other shop aids during original assembly of the parts into the article. However, any special tools required for maintenance shall be supplied with the valve. Special tools are defined as those tool
25、s not listed in the Federal Supply Catalog (copies of this catalog may be consulted in the office of the Defense Contract Administration Service (DCAS). 3.4.4 Springs. Springs shall not be fully compressed during any normal operation or adjustment of the valve. The working stress shall be such that
26、relaxation shall not exceed 5 percent over a 1000 hour period at the nominal operating temperature. Spring ends shall be squared and ground. shall be inc-ed to prevent the accidental loosening of threaded parts. shall not be used, ANSI B-18 hex-head standards shall be used. Each part shall have part
27、 number 3.4.5 Threads. Threads shall conform to Handbook H28. Where necessary, provisions Pipe threads 3.4.6 Pressure-temperature ratinq. Pressure-temperature rating shall be in accordance with 600 pound series in accordance with ANSI B16.5. 3.4.7 End re aration. End connections shall be in-line 2-1
28、/2 inch iron pipe size (ips), 600 pzd-ised-face flanges in accordance with ANSI B16.5. distance between the raised-faces shall be 13 inches (+ 1/16 inch). Valves shall be capable of being installed, operated, adjusted, and maintainedwithin the envelope defined by figure 1. Face-to-face Inlet and out
29、let bore diameter shall be 2.320 f 0.010 inches. 3.4.8 be flanged Bonnet and bottom cover joints. Bonnet and bottom cover (where applicable) shall foraGenttthedy. Joints shall be secured by either of the following$ (a) end. Threads on both bolts and nuts shall be class 2 fit in accordance with Handb
30、ook H28. (b) Tap-end studs with interference fit at the tap end and a class 2 fit at the nut end. Interference fit shall be in accordance with ANSI B1.12. Through-bolts threaded the entire length and fitted with a nut on each 3 Provided by IHSNot for ResaleNo reproduction or networking permitted wit
31、hout license from IHS-,-,-MIL-V-24517(SHIPS) Bonnet and bottom cover shall be located by body guiding (i.e. a close tolerance fit between machined diameters on the body, bonnet, and bottom cover) rather than depending on studs or bolts for location. Spiral wound gaskets shall be fully retained and t
32、he joints shall have metal-to-metal take-up to provide controlled compression of the gaskets. gasket removal, not more than two gasket-retaining faces for each gasket shall be formed on a single part. Suffi- cient bolting area shall be provided to maintain metal-to-metal make-up over at least a 3 ye
33、ar period. Bearing surface of nuts and their respective surfaces on the valve shall be finished machined. forging and be a basic globe configuration with in-line inlet and outlet ports, lines, including the impulse line, shall be internally ported in the body and bonnet. To assure easy Joint design
34、shall assure parallel alinement of the guide bushings. 3.4.9 Body construction. Valve bodies shall be machined from a one-piece casting or All steam 3.4.10 Internal trim. 3.4.10.1 Main valve. The main valve internal trim shall be of cage construction. The quiet-flow regulating-ment and the seat ring
35、 shall be clamped in position by a cage which is either part of, or held in position by, the bonnet or bottom cover flange, This shall permit rapid replacement of all internal trim by avoiding the use of any threads within the valve cavity (such as seat-ring threads). Design shall assure that the ca
36、ge remains under sufficient compression at all times to avoid any movement or looseness and the quiet-flow regulating element shall be confined and compressed on both top and bottom by this cage construction. 3.4.10.1.1 Quiet-flow regulating element. The element design employed to achieve a low-nois
37、e pressure loss shall avoid excessively small flow passages or any other feature jeopardizing operational reliability, It shall be brazed or otherwise fabricated into a one-piece configuration, capable of withstanding installation and operational stresses, Internal passages shall be such that a 0.03
38、3 inch diameter perforated metal screen type strainer installed upstream will protect against clogging. required more often than annually, and replacement due to blockage, erosion, wear, etc., by backflush or with ultrasonic equipment. element shall be supplied with each valve. The element structure
39、 shall be of a solid or Element cleaning shall not be more often than once each 5 years. The element shall be capable of being quickly cleaned _- Special fixtures necessary for cleaning the continuous nature, not susceptible to media migration. 3.4.10.1.2 O eratin piston. The operating piston shall
40、be separate from the main valve and fitted O to 1 percent moisture. (b) (c) Design pressure - 900 lb/in g (strength only). (d) Temperature - Saturation temperature. (e) Flow demand - Minimum% tight shut-off as defined in 3.6.3. (f) (9) Rate of flow demand variation - 800 lb/hr/sec maximum. (h) (i) S
41、hock - As defined by grade A, class I of MIL-S-901. (j) Vibration - As defined by type I of MIL-STD-167-1, Inlet pressures - 250 to 740 pounds per square inch gage (lb/in2g). 2 Range of sustained flow demand - 500 to 10,000 pound per hour (lb/hr). Rate of inlet pressure variation - 30 lb/in2g/sec ma
42、ximum. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- i MIL-V-2 4517 (SHIPS) 3.6 Performance requirements, 3.6.1 Accurac of regulation. Accuracy of regulation, defined as the maximum permis- sible variation in zozstream pressure which can occur w
43、ith the valve set anywhere within the required range of adjustment and then subjected to any number of combinations of service and ambient conditions defined in 3.5, shall be 20 lb/in2g. will not be subjected to sustained flow demands between shut-off and 500 lb/hr. Between flow rates of 500 lb/hr a
44、nd 10,000 lb/hr, at any set point within the range defined in 3.6.4, and at any inlet pressure and transient condition defined in 3.5, the valve shall operate smoothly without hunting, chattering, exceeding the noise criteria specified in 3.6.5, or violating the accuracy of regulation specified in 3
45、.6.1. With a dead-enddownstream volume not exceeding the volume represented by 100 diameters of downstream pipe, any steam leakage from the inlet to the outlet of the valve shall be limited below a value which will cause a discharge pressure buildup of more than 10 lb/in2g in a 1 hour period. 3.6.2
46、Capacity. Valve is required to shut-off tightly as defined in 3.6.3. The valve 3.6.3 Seat tightness. The valve shall meet the following seat tightness requirements: 3.6.4 Range of adustment The valve shall be adjustable over a range of delivered -L-T pressures of 130 to 200 lb/m g. The valve shall m
47、eet the structureborne noise requirements as defined in MIL-STD-740 forype 2 resiliently mounted equipment as measured on the valve body and connecting flanges both parallel and perpendicular to the direction of flow for any combina- tion of operating conditions within the specified limits. 3.6.6 Me
48、chanical shock and vibration. Valves shall be designed to meet the mechanical shock requirements definedygraae A, class I of NIL-S-901 and the environmental vibration requirements defined by type I of MIL-STD-167-1. 3.6.5 Noise. 3.7 Markinp. 3.7.1 Body markings. The manufacturers name or trademark a
49、nd the body material composition shall be cast of forged integral with the valve body. flow arrow shall be cast or forged integral with the valve body or die stamped on raised metal pads (1/8 inch added wall thickness minimum). Each valve shall have an identification plate permanent- ly attached to an exposed position on the valve that will not be covered by insulation, The identification plate shall be made of corrosion-resistant material and shall contain the following information
