Steel-in-Steel Steam Insulated Pipe

Published:2025-07-28 | Last Updated: 2025-07-28    Views: 2

I. What is a steel-jacketed steam insulation pipe?

A steel-in-steel steam insulated pipe is an efficient and safe underground high-temperature steam transportation system. It consists of two layers of steel pipes, with high-performance insulation material filled in between, ensuring minimal heat loss during long-distance steam transportation.

II. Structural Composition of Steel-in-Steel Steam Insulated Piping Systems

(1) Working Pipe (Inner Pipe):  

This is the core of the piping system, directly used for transporting high-temperature steam. It must withstand the high temperatures and pressures of steam, so high-strength, corrosion-resistant seamless steel pipes are typically selected.  

(2) Insulation Layer:  

Tightly wrapped around the outer surface of the working pipe, it is critical to the piping system's insulation performance. Common materials include calcium silicate, glass wool, and rock wool, which have excellent thermal insulation properties and minimize heat loss.  

(3) Sliding or Rolling Supports:  

These components are installed between the working pipe and the outer pipe to support the working pipe and allow it to expand and contract freely due to thermal expansion and contraction. They effectively reduce friction resistance and prevent pipeline damage caused by thermal stress.

(4) Air layer (or insulation layer): 

In some designs, a certain gap is left between the insulation layer and the outer steel pipe. This air layer further enhances insulation performance and serves as a channel for alarm signals in case of leaks.

(5) Outer steel pipe (outer tube): 

This is the outermost protective layer, typically made of ordinary carbon steel pipe. Its primary function is to protect the internal insulation layer and working steel pipe from external environmental factors such as groundwater, soil corrosion, and mechanical damage.

(6) Corrosion-resistant layer: 

The outer steel pipe is typically coated or wrapped with a corrosion-resistant material, such as epoxy coal tar asphalt or fiberglass, to further enhance the corrosion resistance of the outer steel pipe and extend the service life of the entire pipeline system.

III. Main Parameters Table for Steel-in-Steel Steam Insulated Pipes

IV. Main Application Areas of Steel-in-Steel Steam Insulated Pipes

(1) Urban Central Heating Systems  

This is the most typical application area for steel-in-steel steam insulated pipes. In large cities or industrial parks, they are used to transport high-temperature steam or hot water generated by heat sources (such as power plants or district boiler rooms) over long distances to residential areas, commercial buildings, and industrial enterprises, enabling centralized heating and improving energy efficiency.

(2) Petrochemical Industry  

In petrochemical enterprises such as refineries and chemical plants, high-temperature steam is an important process medium. Steel-clad steel steam insulation pipes are used to transport various high-temperature steam, thermal oil, or other process fluids required during production, ensuring stable medium temperature during transportation and meeting production process requirements.

(3) Power Industry  

Thermal power plants are the primary producers and consumers of steam. Steel-jacketed steam insulation pipes are used to transport high-temperature, high-pressure steam generated by boilers to turbines, as well as to transport auxiliary steam and condensate within the plant, reducing heat loss and improving power generation efficiency.  

(4) Other Industrial Sectors  

Textile and Dyeing: Providing stable high-temperature steam required for production processes.

Pharmaceutical industry: Used for steam transportation in production process heating and sterilization.  

Food processing: Also requires high-temperature steam for steaming and disinfection operations.  

Paper industry: Transports steam for pulp steaming and paper drying.  

Metallurgy industry: May also use high-temperature steam in some production processes.

V. Advantages of Steel-in-Steel Steam Insulated Pipes

Significantly reduce heat loss: effectively save energy and lower operating costs.

Ensure stable medium temperature: meet strict temperature requirements of the process.

Improve transportation safety: the sturdy outer steel pipe protects the inner pipe from external environmental damage.

Extend pipe service life: integrated design of corrosion protection, insulation, and strength reduces maintenance frequency.

Suitable for underground installation: saves valuable ground space and beautifies the environment.