Details:

Stainless Steel Fin Tubes is widely used in the recovery of waste heat from boiler flue gas.

Description:
General Manufacturing Process: The fin strip is welded continuously and spirally wound onto a polished bare tube. And the tube and fins are bonded together by using high frequency resistance welding technique.We produce both solid plain and serrated helical welded steel finned tube. And also, all spiral welding tubes could be bent in the middle or at the end of fin tubes, we call it Hairpin tubes.

Basis parameters for helical welded fin tubes:

■ High frequency welding machine output power supply: 200KW or 300KW

■ The High Frequency Resistance Welded Spiral Fin Tube quality is assured by hydrostatic or pneumatic tests and tensile tests in order to verify the mechanical bonding between bare tube and fin materials.

■ Acceptance criteria: INTERNATIONAL STANDARD FOR DIMENSIONS, TOLERANCES, AND TESTS OF HIGH FREQUENCY RESISTANCE WELDED FINS or the delivery conditions (TDC) of clients.

■ Visual check: un-welded parts of fin, fin damage after fining, copper pollution, tears, wrap etc…

■ Dimensional check: fin height, fin spacing, fin inclination, fin corrugation, length of finned & un-finned portion etc…

■ Bending check: ovality, thickness and area reduction.

■ Coating: outside-Red oxide zinc phosphate primer and inside volatile corrosion inhibitor (VCI) in water soluble tablet form.

■ Fin end finish: Bevel(30~35degeree) 

■ Delivery condition: Tube ends are square cut, free burrs, internally dried and air blown clean, externally coated with varnish at both ends of helical welded tubes. The desiccants are put into the each package for continental transportation as well.

■ Documentation shall include QAP, WPS, PQR& WPQ, raw materials mill certificates, inspection and test samples results and warranty certificate of manufacturer.

Applications: 
The High Frequency Resistance Welded Helical Fin Tubes are widely applied in fired heaters, heat exchanger, boilers, economizers, pre-heaters, coolers, heat pipes, heaters etc….

Specifications:
A wide range of fin and tube materials could be combinations are available.

Competitive Advantage:

■ We have more than 10,000 square meters workshop, including 4 ERW high Frequency welding fining lines, daily capacity around 40 Tons;Our quality assurance plan for High Frequency Welding Spiral Steel Tubes.

■ Our quality assurance plan for High Frequency Welding Spiral Steel Tubes.   (2.1) Raw material control for both plain tubes and fins. (2.2) In process control with reports,as WPS, PQR&WPQ; weld deposition efficiency test before fabrication, Non-destructive test and tensile test etc. (2.3) Final inspection control with reports (Visual and dimensional check etc…).

■ The High Frequency Resistance Welded Fin Tube is integrally extended for the max surface area to achieve efficiency. The heat transfer ratio of high frequency welding fin tube is about 8~9 times higher than other plain tubes.

■ This Welded Helical Fin Tubes is a singular integral unit, eliminating heat contact resistance and losses. Generally tube side temperature up to 800 degree for stainess steel fins; Low carbon steels, withstanding up to 475 degree is the most common choice.