NAVY MIL-T-21578 A-1966 TEST EQUIPMENT HAZARDOUS LOCATION INSTALLED BASIC REQUIREMENTS FOR《危险地点安装测试设备的基本要求》.pdf

《NAVY MIL-T-21578 A-1966 TEST EQUIPMENT HAZARDOUS LOCATION INSTALLED BASIC REQUIREMENTS FOR《危险地点安装测试设备的基本要求》.pdf》由会员分享，可在线阅读，更多相关《NAVY MIL-T-21578 A-1966 TEST EQUIPMENT HAZARDOUS LOCATION INSTALLED BASIC REQUIREMENTS FOR《危险地点安装测试设备的基本要求》.pdf（35页珍藏版）》请在麦多课文档分享上搜索。

1、Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-ZLC7BA 44 444470b 02Li5634 4 MIL-T-21578A WIFICATIQNS Military MIL-P-116 MIL-T-704 MIL-M-3171 MIL-F-3541 MIL-S-5002 MIL-A- 5 49 8 MIL-F-5509 MIL- C-5541 MIL-F-7024 MIL- P-7 105 MIL- P-85 85 MIL-F-

2、18280 MIL-P-26915 STANDARDS Federal FED-STD-595 Military MIL-STD-129 MIL-STD-130 Preservation, Methods of Treatment and Painting of Material Magnesium Alloy, Process for Pre- treatment and Prevention of Corrosion on Fittings, Lubrication Surface Treatments and Metallic Coatings for Metal Surfaces of

3、 Weapon Systems Accumulators, Aircraft Hydropneumatic Pressure Fittings, Flared Tube, Fluid Connection Chemical Films and Chemical Film Materials for Aluminum and Aluminum Alloys Fluids, Calibrating, for Aircraft Fuel System Components Pipe Threads, Taper, Aeronautical National Form, Symbol ANPT, Ge

4、neral Requirements for Primer Coating, Zinc Chromate, Low- Moisture-Sens itivity Fittings, Flareless Tube, Fluid Connection Primer Coating, Zinc Dust Pigmented, for Steel Surfaces Colors I Marking for Shipment and Storage I Identification Marking of U. S. Military Property ri I Provided by IHSNot fo

5、r ResaleNo reproduction or networking permitted without license from IHS-,-,-STANDARDS MIL-T-21578A Military (Continued) MIL-STD-143 Specifications and Standards, Order of Precedence for the Selection of MIL-STD-794 Parts and Equipment, Procedures for . Packaging and Packing of MS-28889 Valve, Air,

6、High-pressure Charging MS-33 5 86 Metals, Definition of Dissimilar Air Force-Navy Aeronautical Design AND 10050 Bosses, Standard Dimensions for Gasket Seal Straight Thread Drive, Type XI Engine Accessory Drive, Type XII Engine Accessory AND 20001 AND 20002 (When requesting applicable documents, refe

7、r to both title and number. Copies of unclassified documents may be obtained from the Commanding Officer, Naval Supply Depot (Code 1051), 5801 Tabor Avenue, Philadelphia, Pennsylvania 19120. Requests for copies of classified documents should be addressed to the Naval Supply Depot, via the cognizant

8、Government inspector,) 2.2 Other publications - The following documents form a part of this specification to the extent specified herein. Unless otherwise indicated, the issue in effect on date of invitation for bids or request for proposal shall apply. National Board of Fire Underwriters Standards

9、Article 250 National Electrical Code Article 500 National Electrical Code (Copies of National Electrical Code Standards may be obtained from the National Board of Fire Underwriters, 85 John Street, New York 38, N.Y.) 3. REQUIREMENTS 3.1 Preproduction - The test equipment furnished under this specifi

10、cation shall be a product which has been inspected and passed the pre- production inspection specified herein. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-2157A-49 14999406 012456411 7 W MIL-T-215788 3.2 Selection of specifications and st

11、andards - Specifications and standarcis for necessary commodities and services not specified herein shall be selected in accordance with MIL-STD-143. 3.3 Materials - Materials shall conform to applicable specifications rind shall be as specified herein and on applicable drawings. Materials which are

12、 not covered by specifications, or which are not specifically described herein, shall be of the best quality, of the lightest practicable weight, and suitable for the purpose in tended. 3.3.1 tant material or treated in a manner to render them adequately resistant to corrosion (see 3.6). Metal parts

13、 - All metal parts shall be of a corrosion resis- 3.3.1.1 Dissimilar metals - Unless suitably protected against elec- trolytic corrosion, dissimilar metals shall not be used in intimate contact with each other, Dissimilar metals are defined in MS33586. 3.4 Design and construction - The design and co

14、nstruction of the test stand, various test stand systems, and components shall be in accordance with the following subparagraphs. 3,401 Grouping of systems, components, and cabinet - Design, layout, and assembly of the cabinet and its component parts shall be such as to facilitate quantity productio

15、n and ease of maintenance. The test equipment shall be so desiEed thatno special tools are required for adjustment, cleaning, or main- tenance of the test equipment or any component. 3,4*1,1 Structure - All test equipment shall be located within a fully enclosed metal cabinet suitably designed to wi

16、thstand all loads imposed during service use and shipment. The cabinet shall provide suitable guards or shields for fan blades, heating coils, electrical connections, and all other component parts which may present a hazard to the operator. Instrument panels shall be con- structed of not less than 1

17、1 gage metal; doors and cabinet panels shall be not less than 14 gage metal. 3.4.1.1.1 - Size - Cabinet size shall not exceed 10 feet in length by 8 feet in depth (depth from operators side of stand to rear) by 7-1/2 feet high. Test equipment requiring a cabinet of larger size shall be constructed i

18、n sections to meet the size requirementa, Ail instrumentation located above 6 feet high shall be insortecl in the cabinet so as to be readily visible and accessible to the opera- tor. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-21578A 3.4.1

19、.1.1.1 Sections - Equipment that must be constructed in sections to meet the size requirements shall be so designed that disassembly for shipment and subsequent re-assembly shall not create an alignment probiem of the compo- nents affected. All mating parts, fluid and pneumatic lines, and electrical

20、 connec- tions shall be properly identified by permanent tags and name plates to insure proper re-assembly. 3.4.1.1.2 Base design - All cabinets and sections shall include longi- tudinal channels which shall permit positioninglor moving by means of a fork-lift truck. The base shall be a permanent pa

21、rt of the unit, of sufficient strength and rigidity to support the load without undue stress or strain on the test equipment, and shall be designed to distribute the floor load evenly over the floor space occupied by the test equipment. Channels (or other design as applicable) shall be a minimum of

22、8 inches in width and spaced a maximum of 20 inches between centers. Channels shall be a minimum of 2 inches deep and shall be located to facilitate assembly of test equipment built in sections. Channels shall be located as near the center of gravity of the test equipment as practicable. 3.4.1.1.3 A

23、ccessibility and serviceability - Components shall be arranged within the cabinet to facilitate easy removal, maintenance, and servicing. Lubrication fittings, test locations, filters, shaft seals, and similar components shall be accessible without disassembly or removal of other components, All oth

24、er components shall be readily maintainable. All internal components shall be accessible through rear and side removable doors having quick-detach type hinges and provided with positive flush-type or streamlinged hand latches which are easily operated. TBe hinge pins shall be tapered for ease of ins

25、tallation and the center hinge pin(s) shall be 1/4-inch shorter than the top and bottom pins. Doors shall not exceed 18 inches in width, unless hinged in the center so that when open they shall not extend more than 18 inches from the sides or ends of the unit and shall be readily removable by one ma

26、n. Doors and mating parts shall be constructed to prevent inadvertent scraping of metal parts which might produce sparks. 3.4.1.1.4 Toe clearance - Toe clearance shall be provided at the operators position on the test equipment. This clearance shall be a minimum of 6 inches in height and 4 inches in

27、 depth. 3.4.1.1.5 shall be provided for the operating manual, handbooks, speciaI tools, or auxiliary parts, such as adapters. This container or drawer shall be permafiently attached to the test equipment in a readily accessible location. Storage space - A suitable storage container or drawer 5 Provi

28、ded by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-2157A Li7 9999906 OE“i56113 O W 3,4.1.1.6 Working surfaces - All working surfaces of the test equipment shall be spark-resistant. A suitable surface shall be provided as a desk top for recording test d

29、ata, This surface shall be a minimum of 12 inches wide by 15 inches long; except for the dimensions in 3.4.3.3.1 the distance fromthe floor shall be specified in the detail specification. The longitudinal location of tlie working area shall be placed so that the operator can readily read the gages r

30、ind operate the controls from this location. 3.4J.2 Vibration - The cabinet shall be constructed so that vibration from any components shall not be transmitted through the structural members to the instrumentation to an extent which might impair readability or accuracy. 3.4.1.3 Lights - Lights shall

31、 be of the type approved by the Underwriters Laboratories for Class 1, Division 1, Group D of the National Electrical Code, Article 500-Hazardous Locations. Instrumentation other than direct-reading flow meters, shall not require integral lighting. All direct-reading flow meters shall include integr

32、al lighting. 3.4.1.4 Ventilation - Enclosures shall have air vent louvres near the floor level and at the top or shall be provided with an induction ventilating fan. 3.4.1.5 Air exhausting - The test equipment shall be provided with an air duct exhaust system near the item on test located well below

33、 the face of the operator. It shall provide a down draft movement of air, with suitable ducting ter- minating flush at the top-rear of the stand, No exhaust-air blower or fan shall be required in this system. The capacity and location of the exhaust-air intake shall be such that the operator will no

34、t be subjected to test-fluid vapor during normal operation of the equipment. A metal plate, bearing the estimated exhaust require- ments in cubic feet per minute and the static pressure required to overcome the resistance in the duct work shall be attached on the top of the stand adjacent to the exh

35、aust, The air quantities shall be sufficient to produce a capture velocity at the item being tested of not less than 50 feet per minute. Provisions shall be made for attaching additional duct lengths to the exhaust outlet, 3.4,1,6 Drip pan - A drip pan(s) shall be provided within the en- closure. Th

36、e pan) shall be instailed to catch all leakage which may drip from any component or flow down to the inside walls of the enclosure. Drip pan(s) shall be constructed of not less than 14 gage metal. Pan(s) shall have a minimum of 1 inch slope towards the center of the unit or section. The center shall

37、 be defined as the center of the instrument panel section(s) normally facing the operator. A gutter shall be incorporated into the center of each pan which shall have a minimum of 2 inch slope from front to rear of the stand. The gutter(s) shall terminate with 1 Provided by IHSNot for ResaleNo repro

38、duction or networking permitted without license from IHS-,-,-MIL-T-2L57A 47 7777906 0245b44 2 W MIL-T-21578A inch female coupling(s) for drain connection at the rear of the test equipment unit, located a minimum of 2 inches above the floor. Drain(s) shall be equipped with an approved flame-proof str

39、ainer, accessible for cleaning. Pan(s) shall be adequately reinforced to withstand, without permanent distortion, the combined weight of a 180 pound man and the components being removed or installed, Test equipment constructed in sections shall have individual drip pans installed in such a manner to

40、 prevent leakage between sections, and drip pans shall be installed and supported in such a manner to insure complete drainage of each section, 3.4.2 Electrical systems - 3.4.2.1 Motors - All motors shall be explosion proof and approved by Underwriters Laboratories for Class 1, Division 1, Group D o

41、f National Elec- trical Code, Article 500-Hazardous Locatioiis. All motors shall be rated for con- tinuous-duty service at the specified horsepower. specified, all motors shall be rated for continuous duty at the maximum load imposed during normal test operations. Where horsepower is not 3.4.2.1.1 A

42、C power - AC motors shall operate on 220/440 volt, 3 phase, 60 cycle current and shall be connected for operation on 440 volts. Change over from 440 to 220 voltslshall be possible with the minimum amount of additional parts. The electrical wire used shall be capable of both 220 and 440 volt operatio

43、n, AC motors of 1/3 horsepower or less may be operated on 110 volt, single phase, 60 cycle current by use of a transformer, with the primary leads arranged in such a manner so that they can be selectively connected to any of the three phase legs of the power supply to allow for load balance when the

44、 unit is installed in conjunction with other components. The transformer shall be provided as a component of the test equipment. The transformer may be used to supply 110 volt power for lighting and control circuits. The current rating for continuous operation of the transformer shall be sufficient

45、to adequately supply the 110 volt circuits without overloading. The operating temperature of the transformer shall be within the range specified in the detail specification. 3.4.2.1.2 Push button stations - Push button stations shall operate on 110 volt, single phase, 60 cycle current. 3.4.2.1.3 Rem

46、ote-control components - All remote-control test equipment components, such as motor generator sets or electronic motor controls, which can be located outside a hazardous larea need not be explosion proof. . 3.4.2.1.4 Starters - Motor starters shall be operated by momentary contact push button stati

47、ons. Starters, relays, and fuses shall be located on a remote panel or in the panel of the main control unit (MG set) of the variable speed drive where applicable, in a non-hazardous location. 7 9- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-

48、“-2157 8A 3,4.2,1.5 Pilot lights - Green pilot-lights shall be provided on the basic test unit to indicate when each motor circuit is energized and operating properly, 3,4.2.1.6 interloch - Where there is more than one motor in the equipment and possible damage may be caused by stoppage of any one m

49、otor, interlocks shali be provided so that the stoppage of one motor in the circuit will not damage the equipment. If starting the motors in improper sequence can result in damage, interlocks shall be provided to insure proper sequence. Where cooling water or lubrication are required for components of the test equipment, such as vacuum pump or gear cases, the controls shall be automatic or shall be interlocked with the motor controls in