Table 2.2 I Identification letters for metal thermowells Identification letters for ceramic thermowells Identification letters for thermocouples Table 2.3 I Table 2.4 I Identification letter Brief description Material No. Identification letter Material acc. to DIN 40 685 Part 1 / VDE 0335 Part 1 Identification letter Thermocouples EN 60 584 BF St 35.8 1.0305 CX K 530 / C 530 E NiCr – Cu Ni DU X 18 CrNi 28 1.4749 CY K 610 / C 610 J Fe – CuNi R X 10 CrAl 24 1.4762 CZ K 710 / C 799 K NiCr – Ni D X 15 CrNiSi 2520 1.4841 RSiC Silicon carbide, re-crystalized
1 ) N NiCroSil - NiSil Y Incoloy 800
1 ) 1.4876 SiSiC Silicon carbide, react. bonded
1 ) S Pt10%Rh – Pt CS Kanthal Super
1 ) - R Pt13%Rh – Pt B Pt30%Rh – Pt6%Rh W5 W5%Re – W26%Re L Fe - CuNi (DIN 43 710) ²)
1 )
2 Deviating diameter, please ask for specifications ) DIN-standard withdrawn

3) Description and Dimensions of Metal ThermowellsDescription and Dimensions of Metal ThermowellsDescription and Dimensions of Metal ThermowellsDescription and Dimensions of Metal ThermowellsDescription and Dimensions of Metal Thermowells

Form A Form B Form C Protection tube,round bottom Extendedprotection tube,round bottom Protection tube,weld - in bottom Field formarkingField formarkingField for markingExtensionWelded

Nach Kundenvorgabe z.B.

Example: Thermowell A22D x 1020

Description of a metal thermowell form A with d = 22 mm dia. and thermowell length l

3

= 1020 mm, made from material no. 1.4841 DIN 17 442 (identification letter D as per table 2.2)

Table 3.1

Dimensions and permitted deviations for metal thermowells without pipe screw joint

For straight thermocouples of nominal length l S Form d 250 355 500 710 1000 1400 2000

+0.2 -0.1 ± 0.1

Thermowell length l

3

Permitted deviation +3.0/0 Thermowell l

3

Perm. deviation +5.0/0 15 2 265 370 515 - - - - A / C 24 3 - - 520 730 1020 1420 2020 22 2 - - 520 730 1020 1420 2020 B 22 2 - - - - 1020 1420 2020

Thermowells forms A and C are technically equivalent.

- 4 -