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THERMOWELLS FOR THERMOMETERS AND ELECTRICAL TEMPERATURE SENSORS GENERAL SPECIFICATION FOR

contributor authorNAVY - SH - Naval Sea Systems Command (Ship Systems)
date accessioned2017-09-04T18:09:29Z
date available2017-09-04T18:09:29Z
date copyright09/02/1983
date issued1983
identifier otherGURLDAAAAAAAAAAA.pdf
identifier urihttp://yse.yabesh.ir/std;quein=auth/handle/yse/192528
description abstractThis specification covers wells (thermowells) for use with thermometers and electrical temperature sensors. Older military specifications may still refer to electrical temperature sensors as electrical temperature elements (thermocouple, temperature elements and resistance temperature elements).
Thermowells shall be of the following physical designs to receive the sensors of mechanical thermometers or electrical temperature sensors (see 6.2.1). A military part number system shall identify each variation of thermowell design in accordance with the following: CHART Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, Naval Sea Systems Command, SEA 55Z3, Department of the Navy, Washington, DC 20362 by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter.
Thermowell designs shall be in accordance with the applicable specification sheet number as follows:
   Design symbol                 Design (specification sheet no.)           1                              MIL-T-24270/1          2                              MIL-T-24270/2          3                              MIL-T-24270/3          4                              MIL-T-24270/4          7                              MIL-T-24270/7         12                              MIL-T-24270/12         13                              MIL-T-24270/13         18                              MIL-T-24270/18         21                              MIL-T-24270/21         22                              MIL-T-24270/22         25                              MIL-T-24270/25


Thermowells shall have an internal bore dimension suitable for mechanical thermometers or electrical temperature sensors as follows:
     Symbol          Sensor type            Sensor details         M             Mechanical        MIL-I-17244 and MIL-T-19646        E             Electrical               MIL-T-24388


Mechanical thermometers shall be either bimetallic (MIL-I-17244) or filled system (MIL-T-19646). Electrical temperature sensors shall be either thermocouples or resistance temperature sensors (MIL-T-24388).
Thermowell insertion length shall be one of the following:
      Symbol                   Insertion length (inches)         2                      2        3.5                    3-½ (electrical sensor only)        5.5                    5-½ (mechanical sensor only)        L                      As required to fit the application


Thermowells shall be made of materials as follows:
    Symbol                       Material       CNR                    Copper-Nickel (90-10)      CUNI                   Copper-Nickel (70-30)      CRES                   Corrosion Resisting Steel      NICU                   Nickel-Copper      ALBR                   Aluminum Bronze      CSA                    Steel


Intended Use: The thermowells are intended for use with thermometers and electrical temperature sensors as described in 6.1.1 through 6.1.3. Thermowell designs are intended for use as follows.
                      Insertion Specification          length           Method of   sheet no.           (inches)          mounting                  Application1/       1                    2             ¾ inch         For mounting thermowells in tee                                         NPS socket        fitting, 2 to 4 inches pipe                                                           size with branch connection                                                           ¾ inch NPS socket for socket                                                           welding or brazing the thermowell.       2                    2             ¾ inch         For mounting in tee fitting,                                         NPS socket        2 to 4 inches piping size                                                           with ¾ inch NPS socket size                                                           on branch connection, for                                                           socket welding or brazing the                                                           thermowell.  (See footnote on next page).  Insertion Specification          length           Method of   sheet no.           (inches)          mounting                  Application1/      3                     4            ¾ inch           For mounting in ¾ inch NPS socket                                        NPS socket          boss on piping above 4 inches size.      4                     4            ¾ inch           For mounting in ¾ inch NPS socket                                        NPS socket          boss on piping above 4 inches size.      7                 "M" 5-½        1 inch NPS         Main steam piping 1500 lb/in2,                       "E" 3-½        pilot boss or      1000°F (538°C) maximum, 5 inches                                        integrally         pipe size and larger, steam                                        reinforced         velocity not to exceed 180 ft/sec                                        insert butt        for 5-½ inches (M) or 450 ft/sec                                        welding pipe       for 3-½ inches (E) insertion                                        fitting type       length.  Well material CRES.                                        boss     12                     2            1-⅛ o.d.         Air conditioning and refrigerant                                        socket             systems.     13                     4            1-⅛ o.d.         Air conditioning and refrigerant                                        socket             systems.     18                 L ("M" only)     Pilot boss or      Thermowell for mechanical ther-                       double sup-      integrally          mometers where steam velocities                       port inser-      reinforced          exceed 180 ft/see.                       tion length      insert butt                       depends on       welding pipe                       pipe size        fitting type                       boss     21                     2            Threaded boss,     For mounting thermowells in boss                                        1-5/16-12UN-2B      of material not suitable for                                        size, O-ring        welding or brazing.    22                     4            seal in                                        accordance                                        with MS16142     25                    N/A              N/A             Extension neck adapter.
"M" design is for thermometers in accordance with MIL-I-17244 or MIL-I-19646. "E" design is for electrical sensors in accordance with MIL-T-24388. Thermometer and electrical temperature sensor selection for specific thermowells are in accordance with the following:
MIL-T-24270         Thermowell                MIL-I-17244        MIL-T-19646       MIL-T-24388 1/ specification       insertion                 stem length        Adjustable       Probe compressed sheet no.         length (inches)              (inches)           union                length       l,2,12,21               2                     2 (sensitive      Sensing bulb           2-11/16                                               portion 1-½     1-½ inches                                               inches long       long maximum                                               maximum)  3,4,13,22               4                     4 (sensitive      Sensing bulb           4-11/16                                               portion 3         3 inches long                                               inches long       maximum                                               maximum)  7                   "M" 5-½                 Not applicable    Sensing bulb           4-19/32                     "E" 3-½                 Not applicable 3-½ inches                                              long maximum 18                  "M" only                 Not applicable     Sensing bulb           Not applicable                     (to fit                                     3 inches long                      piping)                                    maximum
See 3.2.
languageEnglish
titleMIL-T-24270Bnum
titleTHERMOWELLS FOR THERMOMETERS AND ELECTRICAL TEMPERATURE SENSORS GENERAL SPECIFICATION FORen
typestandard
page11
statusActive
treeNAVY - SH - Naval Sea Systems Command (Ship Systems):;1983
contenttypefulltext


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