ASME SA192 HFW Serrated Finned Tube with Carbon Steel Fins For Boiler Economizers

ASME SA192 HFW Serrated Finned Tube with Carbon Steel Fins For Boiler Economizers

An ASME SA192 HFW Serrated Finned Tube with Carbon Steel Fins is a high-efficiency tube designed for high-pressure, lower-temperature heat exchange, most famously in boiler economizers. Its combination of code-approved pressure capability, superior ductility, and the heat transfer boost from serrated fins makes it a standard, optimized component for improving boiler efficiency. The selection between SA192 and SA210 ultimately hinges on the maximum metal temperature expected in service.

Here are some detailed breakdowns:

1. Base Tube: ASME SA192 seamless tubes

(1). Chemical Composition (Heat Analysis, %)

The composition emphasizes very low carbon for maximum ductility and weldability.

Note 1: The specified minimum Silicon content ensures the steel is fully deoxidized (silicon-killed), which is crucial for pressure integrity.

(2). Mechanical Properties (at Room Temperature)

These are the minimum guaranteed properties for the finished tube.

2. Fin: HFW Serrated

• HFW: A carbon steel strip is fed continuously, formed into the serrated profile, and welded longitudinally to the SA192 tube using a high-frequency electric current.
  • This creates a strong, continuous, metallurgical bond (a true weld) between the fin root and the tube's outer surface. It is superior to tension-wrapped or embedded fins for high-integrity applications.
• Serrated: This defines the fin geometry.The fins have small, regular cuts or grooves along their height. This "serrated" design:
  • Dramatically increases surface area.
  • Disrupts the laminar boundary layer of the flue gas, creating turbulence.
  • Results in a 25-40% improvement in heat transfer compared to smooth fins of the same size.
  • Helps reduce ash fouling by breaking up the gas flow, making sootblowing more effective.
• Carbon steel fins:It is the most cost-effective choice for applications where the flue gas is not highly corrosive.

#1 Primary Application: Boiler Economizers

This is the dominant and most critical application, consuming the vast majority of these tubes.

What it does: An economizer is a heat exchanger that preheats the boiler feedwater using waste heat from the flue gas exiting the boiler. This significantly improves overall plant thermal efficiency (typically by 4-10%), reducing fuel costs.

#2 Primary Application: Low-Pressure / Low-Temperature Superheaters

In some industrial or smaller power boilers, the initial (primary) superheater section may operate at steam temperatures within the safe limit for SA192.

Caution: This application is less common and requires strict design verification. It is only used when the maximum calculated metal temperature is confirmed to be well below 425°C (800°F).

#3 Secondary Applications (Heat Recovery in Other Systems)

The same "high-pressure, lower-temperature" principle applies in other industries:

• Heat Recovery Steam Generators (HRSGs): Used in the low-pressure evaporator or economizer sections of HRSGs, where the gas temperature from the gas turbine has cooled sufficiently.
• Process Waste Heat Boilers: In chemical, petrochemical, or refining industries, for recovering heat from process gases to generate medium-pressure steam, where gas/steam temperatures are moderate.
• Thermal Oil Heaters: As the pressure-containing tube for the thermal oil, with fins recovering heat from a flue gas stream.