Nailhead Tube For Corrosive Environment

Studded Tube Product Description:

Because of their relative easy of cleaning, studded tubes or nail head pipes are used in furnaces and fired heaters as an alternative to high frequency welded finned tubes wherever the process application is such that heavy fouling of the external surface may occur.

The studs are attached to the pipe in diametrically opposing pairs around the circumference by electrical resistance welding to ensure a high integrity bond for strength and heat flow. Stud diameter, height and pitch can be specified on an individual basis.

Welding tests are carried out as a matter of course to ensure the effectiveness of the stud to pipe bond. Heat treatment of the completed studded tube is carried out where necessary. Should fouling eventually reduce the process performance of the equipment, the studded surface can be cleaned efficiently by shot blasting without damage to the materials.

An electric current is applied by connect on the stud and tube and theresistance in this circuit produces the heat necessary for welding. Maximum resistance and therefore maximum heating occurs at the interface between the Stud and the tube. Pressure to forge the Stud and the tube together at the point of maximum heating is applied by various forms of tooling. These resistance welding processes produce a strong metallurgical bond between the stud and the tube while minimizing the heat affected zone (HAZ) in the tube. The use of pressure to forge the fin and the tube together helps to minimize the heat input necessary to make the weld. This Product is used in Fired Heaters under Very High Pressure & Temperature mainly in Petroleum refineries.

 

Studded Tube(Stainless Steel Welded Tube) Manufacturing Process:

Studs are fully automatically welded onto the tubes (pipes) by resistance welding.

 

Studded Tube(Welded Stainless Tube) Advantages:

To increase the surface area of the tube and to protect tube surface from direct exposure to heat /corrosive environment.

Studding reduces the amount of bare pipes used in these processes. Heat transfer surface of one studded pipe is equivalent to surface of 4 to 10 bare pipes.

Use of studded tubes is ideal for processes/applications, where dirty fuels are used in harsh environments.

 

Studded Tube(Black Welded Pipe) Properties:

Wear proof design

High heat transferring capacity

 

Studded Tube(Weld Galvanized Pipe) Applications：

Boiler,Super heater, Gas furnace burner, heat exchange equipment ,chemical equipment,heat recovery of the petrochemical industry, in areas of convection ovens, vacuum generators for chemical processing, etc.Boiler stud tube,Super heater stud tube, Gas furnace burner stud tube.

 

Studded Tube(Fin Tube) Specifications：

Product Specification
Tube OD	25~273 (mm)	1”~10” (NPS)
Tube Wall Thk	3.5~28.6 (mm)	0.14”~1.1”
Tube Length	≤25,000 (mm)	≤82 ft
Stud Thk	6~25.4 (mm)	0.23”~1”
Stud Height	10~35 (mm)	0.4”~1.38”
Stud Pitch	8~30 (mm)	0.3”~1.2”
Stud Type	Cylindrical, Elliptical, Lens type
Stud to tube surface angle	Vertical or Angular
Material Combinations
Stud Material	C.S. (most common grade: Q235B)
	S.S. (most common grade are AISI 304, 316, 409, 410, 321,347)
	A.S.
Tube Material	C.S. (most common grade: A106 Gr.B)
	S.S. (most common grade are TP304,316, 321, 347)
	A.S. (most common grade are T/P5,9,11,22,91)
Type of Service	High temperature