1、MIL- G-l7489B(SHIPS) 15 March 1961 SUPERSEDING MIL-Ci- 17489A(SHIPS) 13 August 1959 MILITARY SPECIFICATION GAGES, PRESSURE (AIR), BOILER 1. SCOPE 1.1 Scope. - This specification covers boiler air pressure gages suitable for measuring air pressure up to and including 200 inohes of water. of the follo
2、wing types and classes a8 specified (see 6.2): 1.2 Classification. - Air pressure gages shall be Type A - Dial. Type B - Vertical scale. Class 1 - Sngle unit. Class 2 - Dual unit. Class 3 - Triple unit. Class 4 - Multiple unit. Type C - Window. 2. APPUCABLE DOCUMENTS 2.1 The following specifications
3、 and standards, of the issue in effect on date of invitation for bids, form a part of this specification to the extent speci- fied herein. SPECIFICATIONS FEDERAL PPP-B-566 - Boxes, Folding, Paperboard. PPP-B-636 - Box, Fiberboard. PPP-B-665 - Boxes, Paperboard, Metal Stayed (Including Stay Mate- ria
4、l). PPP-B-676 - Boxes, Set-up, Paperboard. MIL-P-116 - Preservation, Methods of. MIL-S-901 - Shockproof Equipment, Class HI (High-Impact) Shipboard Application, Tests for. MIL-D-963 - Drawings, Electrical, Hull and Mechanical Equipment, Naval Shipboard Use. MTL-P-15024 - Plates, Identification Infor
5、- mation and Marking for Identification of Electrical, Electronics and Mechani- cal Equipment. MIL-E-15090 - Enamel Equipment, Light- Gray, (Formula No. 111). MIL-P-15137 - Provisioning and Technical Documentation for Repair Parts for Electrical and MILPTARY Mechanical Equipment (Na- val Shipboard U
6、se). STANDARDS MILITARY MIL-STD-105 - Sampling Procedures and Tables for Inspection by Attributes. MIL-STD-129 - Marking for Shipment and Storage. MIL-STD-167 - Mechanical Vibrations of Shipboard Equipment. (Copies of specifications, standards, drawings, and publications required by contractors in c
7、onnec- tion with specific procurement functions should be ob- tained from the procuring activity or as directed by the contracting officer. ) 2.2 Other publications. - The following documents form a part of this specification to the extent speci- fied herein. Unless otherwise indicated, the issue in
8、 effect on date of invitation for bids shali apply. OFFICIAL CLASSIFICATION COMMITTEE Uniform Freight Classification Rules. (Application for copies should be addressed to the official Ciassification Committee, 1 Park Avenue at 33rd Street, New York 16, New York.) NATIONAL BUREAU OF STANDARDG Handboo
9、k H28 - Screw Thread Standards for Federal Services. (Application for copies should be addressed to the Superintendent of Documents. Government Printing Office, Xashington 25, D. C. ) 3. REQUIREMENTS 3.1 Preproduction. - hior to production, one air pressure gage of each type and class (except type C
10、l, shall be subjected to the tests specified in 4.5 and 4.6 subject to the requirements of 4.2 and 4.2.1. Satisfactory completion of testing of a class 2 gage under type B wiil indicate ability to furnish all classes of type B gages. mercial quality and as specified herein for each type and class of
11、 pressure gage. 3.2 Material. - Material shall be of the best com- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-l7489B(SHIPS) 3.3 Movement. - All parts of the pressure gage movement shall be of corrosion-resisting materials, or shall be prot
12、ected by suitably treating or coating the surfaces. All moving parts shall be as light as practicable, consistent with 3.3.1 and 3.3.2. 3.3.1 All wearing surfaces shall be of metals 3.3.2 The parts subjected to wear shall be of al- which insure minimum friction and wear. loy steel, heat treated or s
13、urface hardened, or of a nonferrous metal. 3.4 Mechanism. - The mechanism shall be de- signed and constructed so that no leakage will occur when the pressure gage is subjected to maximum working pressure at a temperature not in excess of 145F. 3.5 Stopcock, - Each pressure gage shall be pro- vided w
14、ith a three-way stopcock which will enable checking the zero setting at any time without break- ing connection. The stopcock shall be located as near as possible to the threaded connection of the pressure gage. Each pressure gage shall be pro- vided with a flared union coupling suitable for attach-
15、ing to the stopcock. 3.6 Connection. - Pressure gages shall have a 1/4 inch male pipe thread connection, threaded in conformance with Handbook H28. The connection shall be at the bottom, unless otherwise specified (see 6.2). The connection shall extend beyond the case not less than 1-1/8 inches in b
16、ottom connected pressure gages and not less than 1 -1/4 inches be- yond the mounting bosses of back connected pressure gages. The minimum thread length shall be 1/2 inch. 3.7 Repeatability. - Pressure gages shall be of such quality as to insure repeatability within one scale division for the entire
17、scale range. (except type C) of pressure gages sinil satisfacto- riig withstand HI shock in accordance with Specifica- tion MIL-S-901 and vibration in accordance with Standard MTL-STD-167. 3.8 modk and vibration. - All types and classes 3.9 Design. - Pressure gages shall be mechan- ically actuated t
18、hrough the use of diaphragms or other devices without the use of any liquids. The movement of the diaphragms due to differences in pressure shall be magnified by means of a pointer connected to the diaphragms by links of gearing. Design of pressure gage and materials selected shall be adequate to in
19、sure a maximum pressure gage service life of ten years, minimum pressure gage life of five years. with indicating pointers of a plain and unembellished 3.10 Pointers. - Pressure gages shall be fitted design (see figure i). Micrometer adjustable design similar to that shown on figure 1, or other zero
20、 ad- justment feature of the indicating pointer is required so that the scale may be adjusted 5 degrees or 1/2 inch, whichever is greater, in both directions from the normal position. Finished pointers shall be in near mechanical balance. Black pointers shall be furnished. Pressure gages shall be pr
21、ovided with stops at both ends of the diaphragm drive to prevent jamming of the pointer. 3.11 Dials and scales. - The dials and scales for the pressure gages shall be white in appearance with black graduation, figures and letters. Marking shall be neatly and accurately lithographed, silk-screened, c
22、ut or etched and filled with dead black enamel. Dials and scales for gages with a pointer shall be made of sheet steel or aluminum adequately protected from corrosion. Scale markings shall be of sufficient size to be seen by normal eyes at a distance of 20 feet except for those intended for control
23、panel instal- lation (see 3.15. l) and except as modified in 3.16.4 for type C gages. 3.12 Cases. - Cases shall be made of sheet steel or aluminum adequately protected from corrosion. Cases shall be free from warpage, checks and chip- ped or blistered surfaces. There shall be no burrs or projecting
24、ridges at the dividing line of mold, nor an unsightly finish at this point caused by chipping, filing, or grind without subsequent buffing or polish- ing. Cases shall be painted gray conforming to class 2 of Specification MIL-E-1 5090, unless otherwise specified in the contract or order. 3.13 Identi
25、fication plates. - Identification plates shall be furnished in accordance with Specification MIL-P-15024 with each gage either mounted on the gage or for mounting on the panel board directly un- der the pressure gage. The identification plate shall show the purpose for which the pressure gage is in-
26、 tended (see 6.2). 3.13.1 in addition to the identification plates spec- ified in 3.13 each pressure gage shall be marked with the manufacturers name or trademark. 3.14 Type A, dial.- 3.14.1 w. - Dials shall be as shown on figure 2 in respect to character and design. Pressure gages shall be accurate
27、ly and correctly graduated up to and including the last scale division of the scale. The graduation shall cover an arc not less than 270 de- grees. Dials shall be secured to the pressure gage mechanism by at least 3 screws. The scales shall be graduated to read the pressure effective on the diaphrag
28、m in inches of water above atmosphere (bar- ometric) unless other graduations are specified. 3.14.1.1 The diameter of the dial, height of the figures and diameter of graduated dial circle thereon, shall be as shown in table I. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted wi
29、thout license from IHS-,-,-Table I - Dimensions of type A dials. Size of pressure gage Inches 8-1/2 Diameter Height of Diameter of grad- of dial figures uated dial circles minimum1 Inches Inch Inches 8-1/4 1 /2 7 1 Linear scale 0-90 degrees Range Inches Inches 0-140 0-10 0-170 0-15 0-200 0-1 5 3.14.
30、1.3 The first 90 angular degrees of the dial arc shall cover the inches of water specified in table II divided into 2/10 inches of water with nu- merals every inch. The l inch and 2/10 inch scale graduations shall be easily distinguished from one another. The remainder of the scale shall cover at le
31、ast 180 angular degrees of the dial arc with suffi- cient numerals and scale graduations for good and accurate readibility. 3.14.2 Actuating mechanism. - The actuating mechanism between the pointer and the diaphragms shall be such that the pointer will move in an arc of a circle not less than 270 de
32、grees. 3.14.3 Accuracy. - Type A pressure gages shall be of such design and construction as to insure main- tenance of accuracy to within plus or minus one scale division for the 90 degree portion of the scale range, and for the remainder of the scale range, within plus or minus 2 percent of the tot
33、al scale range (see 4.5.3). 3.14.4 Cases. - Cases shall conform to the de- sign requirements specified in 3.12. In addition, design character and dimensions shall be as shown on figure 3. Dimensions other than those for the mounting bolt holes shall be considered nominal, and reasonable variations w
34、ill be permitted. Linear scale 90-270 degrees Inches 10-100 15-150 15-200 MIL - G- 1 74 89 B (SHIPS) 3.14.5 Movement. - Movement shall be secured to the socket in a manner independent of the case. 3.14.6 Sockets. - Sockets shall be made of bronze or brass. Sockets shall be provided with amintegral w
35、rench grip of 1/2 inch minimum width outside the case, threaded for the iron pipe size connection. The socket shall be secured to the case by not less than 3 screws in such a manner that working or twisting of the pressure gage case shall not cause movement of the pointer. 3.15 Type B, vertical scal
36、e. - 3.15.1 Pressure gage scales. - Scales shall be as shown on figure 4 in respect to character and design except for ranges and number of units. Pressure gages shall be accurately and correctly graduated up to and including the last division of the scale. Scales shall be secured to the pressure ga
37、ge mechanisms by at least 4 screws. nie scales shall be of material as specified in 3.11. The scales shall be graduated to read the pressure effective on the diaphragm in inches of water above atmosphere (barometeric) unless other graduations are specified in the contract or order. The height of fig
38、ures on the scale shall be 1/2 inch. Scales with a range of up to and including 15 inches of water shall have numerals at each inch of water. Each inch graduation shall be divided into 1/10 inch graduation. The 1 inch, 1/2 inch and 1/10 inch grad- uations shall be easily distinguished from each othe
39、r. Scales with a range up to and including 60 inches shall have numerals every 5 inch graduation. Scales up to and including 100 inches shall have numerals every 10 inch graduation. The graduation shall be in inches with the 10 inch, 5 inch and 1 inch graduations easily distinguished from each other
40、. Scales with a range above 100 inches of water shall be marked with suffi- cient graduations for good and accurate readability. Minimum size of scale shall be 2 inches by 10 inches, except that for gages intended for control panel in- stallation, scales may be a minimum of 2 inches by 6 inches. 3.1
41、5.2 Actuating mechanism. - The actuating mechanism between the pointer and the diaphragms shall be such that the pointer shall move in a vertical plane for a minimum distance of 10 inches, except that for control panel installation this minimum dis- tance may be 6 inches. 3.15.3 Accuracy. - Gages sh
42、all be of such design and construction to insure maintenance of accuracy to within plus or minus 2 percent of total scale range (see 4.5.3). 3.15.4 Type B, class 1, vertical scale, single u however, the sample sizes shall be as specified in the applicable table of Standard MIL-STD-105 and the accept
43、ance number shall be zero until the AQL permits one or greater. 4.4 Examination. - 4.4.1 Examination and calibration. - Before submission for the examination specified in 4.4.2, and in accordance with 4.5.3, the contractor shall examine and calibrate each gage. 4.4.2 Visual and dimensional examinati
44、on. - Fach of the sample gages selected in accordance with 4.3.2 shall be visually and dimensionally examined to verify compliance with the requirements of this specification as to material, finishes, work- manship, dimensions and scale or dial markings. Any gage in the sample containing one or more
45、 visual or dimensional defects shall be rejected and if the number of defective gages in any sample exceeds the acceptance number for that sample, the lot represented by the sample shall be rejected. 4.5 Test procedures. - 4.5.1 Temperature test. - The pressure gages shaU be subjected to a temperatu
46、re of 145F. for a period of not less than 6-hours. 4.5.2 and the fact that the Government may have formulated, furnished, or in any way supplied the said drawings, specifications, or other &ta, is not to be regarded by implication or otherwise as in any manner licensing the holder or any other perso
47、n or corporation, or conveying any rights or permission to manufacture, use, or sell any patented invention that may in any way be related thereto. Preparing activity: Navy - Ships (Project 6685-NO3OSh) 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,
48、-,-1 TOP VIEW I BOTTOM VIEW SH33BS Figure 1 - Micrometer indicating pointer (adjustable). MIL-G-l7489B(SHIPS) 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-1748SB bb W 999990b 0129492 b W MIL- G- 17489 B(SHIPS) 10 Provided by IHSNot for Res
49、aleNo reproduction or networking permitted without license from IHS-,-,-flIL-G-L7489B bb D 999990b 0129473 8 9 I w I 11 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-L7LI9B bb 799990b 0129474 T - MIL - G- 17489 B(SHIPS) LL LINEAR SCALES -100 - 90 - 80 - 70 -60 -50 -40 30 - - - - - P- - - CI - - 15 I) INCHES -WATER UUSA Figure 4 - &ales and indicating pointers. 12 Provided by IHSNot for ResaleNo reproduct
