Highest allowable surface load for commonly used materials in electric heating pipe standards, Source: People's Republic of China Machinery Industry Standard JB/T2379-2016 "Metal Tubular Electric Heating Element"
5.1.5 Materials:
The materials used to manufacture components should be reasonably selected according to their use requirements, should consider the working conditions, and should meet the provisions of their quality standards.
Common materials for component metal tubes, their allowable media characteristics and maximum operating temperature See Table 1.
The highest allowable surface load of commonly used materials for component metal tubes in common media shall comply with the provisions of Table 2.
The insulation filler material should be selected according to the operating temperature of the component. When the working temperature T≤ 400 °C, fill low-temperature magnesium oxide powder; When the working temperature is 400 °C< T≤ 600 °C, fill with medium temperature magnesium oxide powder; When the working temperature is 600 °C< T≤850 °C, fill with high-temperature magnesium oxide powder. Brass exit rods shall not be used for components with a maximum temperature above 450°C or temperatures exceeding 450°C that may be encountered during their processing.
Table 2
Heating medium and its codename
Surface load
W/cm2
Metal pipe materials and their grades
Still air Q
2
Carbon steel 10
5
Stainless steel: 06Cr18Ni10(304);06CCR18Ni10Ti(321);
06Cr17Ni12Mo2(316);022Cr17Ni14Mo2(316L)
7.5
Stainless steel: 06Cr25Ni20 (310S); Alloy incoLoy 840:
10
Alloy: incoLoy 800; incoLoy800H; Inconel 600
Flowing air L
Flow rate≥ 6m/s
2.5
Carbon steel 10
5.5
Stainless steel: 06Cr18Ni10(304);06CCR18Ni10Ti(321);
06Cr17Ni12Mo2(316);022Cr17Ni14Mo2(316L)
8
Stainless steel: 06Cr25Ni20 (310S); Alloy incoLoy 840:
11
Alloy: incoLoy 800; incoLoy800H; Inconel 600
Water, weak acid, weak alkali solution boiling S
7
Copper T4
9
Carbon steel 10
Water, weak acid, weak acid solution boiling S
11
Stainless steel: 06Cr18Ni10(304);06CCR18Ni10Ti(321);
06Cr17Ni12Mo2(316);022Cr17Ni14Mo2(316L)
13
Stainless steel: 06Cr25Ni20 (310S); Alloy incoLoy 840:
15
Alloy: incoLoy 800; incoLoy800H; Inconel 600
Food oil, lubricating oil
Hydraulic oil Y
rest
0.7
Carbon steel 10;
Stainless steel: 06Cr18Ni10(304);06CCR18Ni10Ti(321);
06Cr17Ni12Mo2(316);022Cr17Ni14Mo2(316L)
flowing
1.5
Flowing heat transfer fluid
2.5
Stainless steel: 06Cr18Ni10Ti(321);
Fuel oil R
4
Stainless steel: 06Cr18Ni10Ti(321);06Cr17Ni12Mo2(316);
022Cr17Ni14Mo2(316L)
Components are cast, flush-mounted, pressed in aluminum, copper
M in materials such as steel
13
Carbon steel 10;
Stainless steel: 06Cr18Ni10(304);06CCR18Ni10Ti(321);
022Cr17Ni14Mo2(316L)
High pressure, medium to high operating temperature water A
2.5 (2.0 at high temperature)
Stainless steel: 06Cr18Ni10Ti(321);06Cr18Ni20(310S);
Alloy: IncoLoy 840
3 (2.5 at high temperature)
Alloy: incoLoy 800; incoLoy800H; Inconel 600
Note: () is a U.S. steel grade.
