Heating Cable
A heating cable (also known as a heat tracing cable or electric heating cable) is a special type of cable that converts electrical energy into thermal energy, used for freeze protection and insulation or process temperature maintenance of pipelines, storage tanks, and equipment surfaces. Its core function is to compensate for the heat loss of the object being traced through heat conduction, and it is widely used in petrochemical, power, construction, fire protection, food and pharmaceutical industries.
I. Main Types and Application Scenarios
Type Core Features Typical Application Scenarios Key Selection Considerations
Self-regulating heat tracing cable Based on the positive temperature coefficient (PTC) characteristics of PTC materials, resistance increases and current is automatically limited as temperature rises; can be cut to any length and installed with crossover overlap Conventional freeze protection for fire protection pipelines, water supply and drainage pipes, process water pipes, etc. Single-run length is limited (usually ≤100 m); the starting current of new-generation products has been reduced to 0.2–0.3 A/m
Constant power heat tracing cable Output power per unit length is constant; must be used with a thermostat; crossover overlap is strictly prohibited Heavy oil pipelines, chemical reactors, high-temperature material transfer pipelines Divided into parallel type (single run ≤100 m) and series type (single run can reach thousands of meters)
MI mineral insulated heating cable Metal sheath + magnesium oxide mineral insulation; high temperature resistance, explosion-proof, corrosion-resistant, and high mechanical strength Petrochemical reaction units, offshore platforms, nuclear power, and other extremely harsh working conditions Temperature resistance up to 600°C–800°C; insulation resistance >1000 MΩ/1000 V; bending radius ≤6 times outer diameter
II. Core Selection Points
Operating temperature range (primary parameter): determined according to the minimum ambient temperature of the medium and the process maintenance temperature.
Low-temperature freeze protection (0–105°C): self-regulating heat tracing cable is sufficient
Medium-high temperature maintenance (around 150°C): constant power heat tracing cable
Ultra-high temperature environment (up to 600°C–800°C): MI mineral insulated heating cable must be selected
Power density (W/m): must match the calculated heat loss of the pipeline; too low will cause freeze protection failure, while too high can easily burn out or accelerate aging. Common power density is 10–60 W/m, and high-power models can reach above 80 W/m.
Explosion-proof and corrosive environments: in flammable and explosive areas such as petroleum and chemical industries, products with explosion-proof certification (Ex d IIB T4 or Ex ib IIB T4) must be selected; for acid, alkali, and oil-contaminated environments, FEP/fluoroplastic or chloroprene rubber corrosion-resistant sheaths must be selected.
Electrical parameter matching:
Rated voltage: commonly 220 V/380 V, must match on-site power supply
Insulation resistance: should be ≥50 MΩ at room temperature; MI cable should be >1000 MΩ/1000 V
Withstand voltage level: factory test ≥1200 VAC/1 min
Power supply cable selection: calculate current according to the total power of the heating cable and reasonably select the power supply wire diameter.
5 kW equipment: 220 V single-phase recommended 6 mm² copper wire; 380 V three-phase recommended 2.5 mm² copper wire
15 kW equipment: 220 V single-phase recommended 16 mm² copper wire; 380 V three-phase recommended 4 mm² copper wire
30 kW equipment: 220 V single-phase recommended 50 mm² copper wire; 380 V three-phase recommended 16 mm² within 50 m; 25 mm² recommended for over 50 m or high-temperature environments
For lines exceeding 50–100 m, voltage drop must be calculated and the wire diameter increased by one grade
Installation conditions: in areas with many bends or requiring crossover overlap installation, self-regulating heat tracing cable must be selected, and constant power cable is strictly prohibited; heating cables for floor radiant heating must have a grounding shielding layer, and the outer diameter should not be less than 5 mm.
III. Local Manufacturer Resources (Yangzhou Area)
Yangzhou and its surrounding areas are an important industrial cluster for electric heat tracing and electric heating equipment in China. The following local manufacturers can be referenced for selection:
(Xiaoguanzhuang Town, Baoying County): mainly produces MI mineral insulated heating cables, self-regulating/constant power heat tracing cables, cast copper/cast aluminum/cast iron heaters, electric heating tubes, etc. The products are widely used in petroleum, chemical, power, West-East Gas Pipeline and other fields, and exported to Northern Europe and the Far East.
(Baoying County): business scope covers R&D, manufacturing, and sales of electric heaters, electric heat tracing, electric heating tubes, mineral cables, electric heat tracing materials, etc.
Mainly engaged in self-regulating/constant power heat tracing cables, heating cables, armored cables, skin effect cables, explosion-proof control boxes and cabinets, electric heaters, etc., with 35 registered trademarks and 5 patents.
Yangzhou Belkart Electric Co., Ltd. (Liubao Town, Baoying County): business scope covers explosion-proof electric heaters, electric heating tubes, heat tracing cables, power testing instruments, temperature control cabinets, etc. Products involve petrochemical, power and other industries.
Nearby manufacturers: Anbang Electric Co., Ltd. in Tianchang, Anhui (adjacent to Yangzhou) is one of the leading enterprises in temperature-controlled electric heat tracing in China, and its products are widely used in national-level projects such as the West-East Gas Pipeline and offshore oil platforms; Wuhu Jiahong New Materials Co., Ltd. has an annual production capacity of 70–90 million meters, has passed UL, CE, ATEX, DNV and other international certifications, and won a three-year framework agreement with CNOOC.
IV. Usage Precautions
Constant power cable crossover overlap is strictly prohibited: crossover overlap of constant power heat tracing cable will cause local overheating and burnout; self-regulating type may be crossover overlapped.
Reliable grounding: the metal braided layer of explosion-proof reinforced cable must be reliably grounded, with grounding resistance ≤4 Ω.
Standardized cold lead-hot lead joints: cold lead-hot lead joints should be connected using factory-specific processes; simple on-site twisting is strictly prohibited, and grounding continuity and sealing must be maintained.
Insulation test before installation: insulation resistance testing is required before and after laying to ensure it is ≥ the minimum value specified by the manufacturer.
Thermostat matching: constant power heat tracing cable must be used with a thermostat; although self-regulating type can control temperature automatically, adding a thermostat is recommended to save energy and extend service life.
Regular inspection and maintenance: check insulation resistance, joint sealing, and thermostat operating status to prevent safety accidents caused by insulation aging.
Heating cable selection requires comprehensive consideration of six dimensions: temperature requirements, power density, explosion-proof grade, corrosion protection requirements, power supply matching, and installation conditions. If you have a specific application scenario (such as pipeline medium, maintenance temperature, pipeline length, whether it is an explosion-proof area), I can help you further refine the selection recommendations.
