Heating Tubes and Heating Rods
Analysis completed, with reference to 16 sources, including official data from Tubatu and others
Heating tubes and heating rods are the most basic and widely used core heating elements in the field of industrial electric heating. They convert electrical energy into thermal energy to achieve direct heating of media such as liquids, gases, and solid molds. Their selection must strictly match the medium characteristics, temperature requirements, power density, material corrosion resistance, and installation space; otherwise, it can easily lead to a sharp drop in service life, soaring energy consumption, or even safety accidents.
I. Main Types and Applicable Scenarios
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Type Core Features Typical Operating Temperature Applicable Scenarios
Single-head heating rod (cartridge tube) Single-end wiring, small size, high power density ≤700℃ Injection molds, hot runner systems, narrow spaces in small equipment
U-shaped/W-shaped electric heating tube Double-end wiring, flexible structure, easy to fix ≤450℃ Water tanks, oil tanks, air ovens, air duct heating
Flange-type electric heating tube Multiple combined, high pressure resistance, easy to disassemble and assemble ≤450℃ Large water/oil storage tanks, reactor jackets, pipeline heating
Finned electric heating tube Surface equipped with heat dissipation fins, increasing heat exchange area ≤450℃ Air dry burning, hot air circulation ovens, air duct heating
Titanium alloy heating tube Resistant to strong acids and alkalis, seawater corrosion ≤300℃ Electroplating tanks, PCB etching lines, seawater desalination, chemical solutions
Quartz/infrared heating tube Extremely fast heating, infrared radiation heating ≤1100℃ Food drying, plastic thermoforming, instantaneous high-temperature heating
Silicon carbide/silicon molybdenum rod Ultra-high temperature, oxidation resistant 1200~1800℃ Industrial kilns, sintering furnaces, ceramic firing
II. Core Selection Points
1. Surface load (the first indicator of service life)
Surface load refers to the power per unit heating area (W/cm²). The lower the value, the lower the tube wall temperature and the longer the service life:
Liquid heating: natural convection in water 1~3W/cm², forced circulation 5~8W/cm²; oil medium 2~4W/cm², under stirring conditions 6~10W/cm²
Gas dry burning: ordinary hot air (200~400℃) ≤3~5W/cm²; ultra-high temperature dry burning (400~600℃) ≤1.5~3W/cm²
Mold heating: power density is recommended to be controlled below 30W/cm². For high power density scenarios (≥45W/cm²), small-diameter high-power technology products should be selected
2. Tube material (according to medium and temperature)
304 stainless steel: ≤450℃, ordinary water, air, low-temperature oil, highest cost performance
316/316L stainless steel: resistant to weak acids and alkalis, chloride corrosion, first choice for food and pharmaceutical/chloride-containing water
321 stainless steel: ≤550℃, resistant to high-temperature creep, medium and high temperature ovens, heat transfer oil
310S (2520) stainless steel: ≤700~800℃, ultra-high temperature ovens, annealing furnaces
Titanium and titanium alloys: ≤300℃, seawater, strong acids and alkalis, electroplating solutions, air dry burning strictly prohibited
Incoloy 800/840 nickel-based alloy: 750~900℃, long-term continuous ultra-high temperature dry burning, sulfur-containing flue gas environments
Quartz tube: ≤1100℃, instantaneous high-temperature infrared heating, fragile and unable to withstand pressure
3. Power calculation
Liquid heating: Power (kW) = mass flow rate (kg/h) × specific heat capacity (kJ/(kg·℃)) × temperature difference (℃) ÷ 3600 ÷ thermal efficiency (0.9~0.95)
Gas heating: Power (kW) = volume flow rate (m³/h) × density (1.2kg/m³) × specific heat capacity (1.005) × temperature difference ÷ 3600 ÷ thermal efficiency (0.8~0.9)
Mold/solid heating: Power (W) = workpiece mass (kg) × specific heat capacity (J/(kg·℃)) × temperature difference (℃) ÷ heating time (s) ÷ thermal efficiency (0.6~0.8), plus heat dissipation compensation power
Safety margin: reserve 10% for intermittent operation, 20% for continuous operation, and 30% for outdoor/high heat dissipation scenarios
4. Structure and installation
Single-head rod: tube diameter φ6~φ23mm, installation clearance recommended ≤0.05mm on one side, tube diameter about 0.1mm smaller than the mold hole diameter
U-shaped/flange type: suitable for water tanks and oil tanks, convenient for multiple combinations and disassembly and maintenance
Finned type: mandatory for air heating, heat dissipation area expanded by 2~3 times, avoiding burnout of straight tube dry burning
5. Safety protection
Anti-dry burning: liquid heating must be equipped with liquid level detection + temperature controller + limit temperature switch
Insulation resistance: cold state ≥500MΩ, high-frequency continuous operation recommended ≥1000MΩ
Explosion-proof certification: flammable and explosive working conditions must use Ex d IIB T4 or above explosion-proof type, with explosion-proof certificate
III. Local Manufacturer Resources (Yangzhou and Surrounding Areas)
Jiangsu is the core industrial cluster for electric heating elements in China, with many manufacturers in Yangzhou and surrounding areas. The following can be used for selection reference:
Yangzhou local manufacturers:
Mainly engaged in plate-type electric heaters, electric heating tubes, etc. Products are widely used in industrial scenarios such as electric precipitator ash hopper wall insulation and dewatering bin door insulation.
Mainly engaged in silicone rubber heating belts, cast aluminum heating plates, electric heating tubes, etc., supporting non-standard customization, suitable for mainstream equipment such as Sany and XCMG. (Xiaji Town, Baoying County): founded in 1985, with 14 patents and ISO9001 certification, mainly engaged in industrial electric heating tubes, heaters, and sensors. (Guangling District): mainly engaged in electric heating appliances, heating rings, heating plates, heating tubes, ceramic heaters, etc. (Chengnan Industrial Concentration Zone, Baoying County): mainly engaged in electric heaters, crawler-type heaters, bolt heating rods, electric heating tubes, electric heating cables, etc. (Production base: Xiaji Town, Baoying County): mainly engaged in stainless steel electric heating tubes, stainless steel electric heating rings, liquid heaters, mica electric heating rings, etc.
Mainly engaged in stainless steel heating rings and stainless steel heating plates (mica heaters), widely used in extruders, injection molding machines, hot pressing templates, etc.
Surrounding neighboring manufacturers (Yancheng/Zhenjiang/Taizhou/Xinghua, 1~2 hours' drive from Yangzhou):
Using 304/316L stainless steel and titanium alloy substrates, temperature resistance from -20℃ to 800℃, insulation resistance ≥100MΩ, supporting full-spec customization of U-shaped, finned, flange, etc., non-standard customization delivered within 7 days, urgent orders expedited within 24 hours.
Certified by ISO9001/14001/45001 three-system certification and CE certification, mainly engaged in finned heating tubes, liquid heating tubes, mold heating rods, cast aluminum/cast copper heating plates, explosion-proof electric heaters, providing full-process services from selection to after-sales.
Focused on industrial-grade electric heating tubes for more than ten years. Main products include single-head heating rods (φ6~φ25mm), U-shaped special electric heating tubes, finned heating tubes. Flange electric heating tubes have a pressure resistance stability measured at 1800V/1min with a pass rate of 99.3%, and have been supplied in batches to a leading injection molding machine manufacturer in Jiangsu.
The product matrix covers electric heating tubes, cast aluminum electric heating rings, silicone heating films, far-infrared quartz heating tubes, etc. Cast copper heating plates have market recognition in electric hot pot and induction cooker base heating modules.
Can customize imported material high-temperature heating rods in non-standard sizes. Tube materials include Japanese imported SUS310S, American imported Incoloy800/840, etc., suitable for ovens, mold tool heating, and other scenarios.
Mainly engaged in pipeline heaters, flange heaters, air duct heaters, heat transfer oil heaters, etc. The product line covers various specifications from 5KW to 80KW, supporting stainless steel/explosion-proof customization.
Joint venture enterprise, certified by ISO9000, mainly engaged in electric heating tubes for boilers, electric heating tubes for ovens, single-head electric heating rods for molds, electric heaters for air ducts/oil tanks/pipelines, silicon carbide electric heating plates, etc.
Focusing on small and medium power (50~1200W) electric heating tubes. Products are mainly mica sheet wrapped type and ceramic base direct plug-in type. Heating to rated temperature ≤90s, widely used in OEM projects for coffee machines, dishwashers, commercial steam generators, and other home appliances.
IV. Usage Precautions
Dry burning strictly prohibited: liquid heating tubes must not be energized without water/liquid, they can burn out in a few minutes
Clean before installation: remove oil stains and rust from mold holes/container inner walls to ensure the heating tube fits tightly with the heated body
Insulation testing: before use after long-term storage, measure insulation resistance with a megohmmeter. If below standard, dry before energizing
Wiring specifications: terminals must be waterproof and dustproof (IP54 or above), high-temperature areas should use ceramic or metal sealing, and the shell must be effectively grounded
Avoid frequent start-stop: prevent thermal expansion and contraction from causing tube cracking and powder leakage
Supporting temperature control: high-temperature working conditions must be equipped with PID precise temperature control and over-temperature protection to prevent empty burning and over-temperature
The selection of heating tubes/heating rods requires comprehensive consideration of six dimensions: medium characteristics, surface load, tube material, power calculation, structural installation, and safety protection. If you have specific application scenarios (such as heating medium, temperature requirements, power requirements, installation space), I can help you further refine the selection plan or recommend suitable local manufacturers.
