Abstract

Improper surface load design is the leading cause of electric heating tube failure. This article teaches you how to scientifically balance power and service life.

 

Main Body

In the electric heating industry, there is a critical parameter: Surface Load, typically expressed in W/cm². Simply put, it is the power carried per unit area.

 

Maximum Load Limits for Different Media

Flowing water heating: recommended 6–10 W/cm²

 

Mold heating (heat transfer limited by gap spacing)

recommended 2–4 W/cm²

 

Still air heating

recommended ≤ 1–2 W/cm²

 

Why Does Overloading Cause Burnout?

If the surface load is too high, the internal heat cannot be transferred quickly enough to the heated medium. The resistance wire temperature then rises rapidly beyond its melting point, leading to wire breakage or

sheath melt‑through – commonly known as “tube burst”.

 

2026 New Standard: Non‑Linear Power Distribution

In today’s precision industrial heating applications, we achieve non‑linear power distribution by varying the winding density of the resistance wire – lower power at both ends and higher power in the middle. This design

effectively compensates for heat loss along the tube, resulting in a more uniform temperature profile across the entire heating zone.

 

Recommendation

Before placing an order, be sure to inform our technical team of your specific operating environment. We will provide you with an optimized surface load design solution.