ASME SA179 Seamless Heat Transfer Tubes

What Is ASME SA179 Seamless Heat Transfer Tube

ASME SA179 is an ASME standard specification covering cold-drawn low-carbon seamless heat transfer tubes, specially designed for medium and low temperature heat exchange equipment heating surfaces, including boiler economizers, low-temperature superheaters, condensers, air preheaters and industrial shell & tube heat exchangers.

The tube adopts full cold-drawn forming process, with ultra-precise outer diameter and wall thickness tolerance, smooth inner and outer surface without oxide scale, uniform heat conduction performance, stable mechanical property under long-term medium-temperature flue working condition. The base material is low carbon killed steel, with good bending, stamping and welding performance, easy on-site boiler overhaul cutting and processing.

Compared with hot-finished seamless tubes, SA179 cold drawn tubing features thinner wall thickness, tighter dimensional tolerance and cleaner surface, which is the mainstream standard heating surface tube widely adopted by overseas thermal power plant and industrial boiler projects.

Key Advantages of ASME SA179 Heat Transfer Tube

• Strict ASME SA179 standard compliance: Full chemical composition, mechanical property and hydrostatic test according to ASME boiler & pressure vessel code
• Cold drawn precision forming: Ultra-tight OD & WT tolerance, consistent wall thickness for uniform heat exchange efficiency
• Smooth inner & outer surface: No scale, crack or scratch, reduce medium flow resistance and avoid local overheating risk
• Stable medium temperature performance: Long-term safe operation below 450℃, ideal for boiler tail heating surfaces
• Excellent machinability: Good cold bending, flaring and welding performance, convenient fin processing and field repair welding
• Low carbon base material: Low tendency of hardening after welding, no post-heat treatment required for conventional welding joints
• Complete inspection traceability: Each batch supplied with MTR material test report, chemical spectrum & tensile test records for power plant acceptance
• Full specification customization: Custom outer diameter, wall thickness and fixed length to match all mainstream boiler heating surface layout drawings

ASME SA179 Mandatory Chemical Composition (wt%)

Note: ASME SA179 requires fully killed low carbon steel ingot, rimmed steel is not allowed for heat transfer tube production.

Mandatory Mechanical Properties After Normalizing Treatment

Common Standard Sizes of ASME SA179 Heat Transfer Tubes

Conventional stock sizes match global mainstream boiler economizer & low superheater layout, non-standard OD, wall thickness and fixed length support full drawing customization:

Tolerance control: Outer diameter tolerance ±0.10mm, wall thickness tolerance ±0.15mm for cold drawn finished tubes, far tighter than hot finished seamless pipe standards.

Full Production Flow of ASME SA179 Cold Drawn Heat Transfer Tube

1. Raw billet inspection: Spectral chemical composition test of low carbon killed steel round billet, verify compliance with SA179 element limits
2. Hot piercing: High temperature perforate round billet into primary seamless hollow shell
3. Intermediate annealing: Eliminate piercing internal stress for subsequent cold drawing processing
4. Cold drawing forming: Multi-pass precision cold drawing to target outer diameter & wall thickness size
5. Final normalizing heat treatment: 650~700℃ full furnace normalize to reach SA179 mechanical property requirement
6. Straightening & polishing: Straighten tube body, remove surface oxide scale & drawing scratches
7. Cut to fixed length: Saw cutting to customer specified project length, deburr pipe ends
8. Full line inspection: Hydrostatic test, eddy current flaw detection, dimensional calibration & sampling tensile test

Full Set Matching Boiler Tube Protection Fittings For SA179 Tubing

Main Applicable Equipment & Working Zones

ASME SA179 seamless heat transfer tube is limited to medium-low temperature heating surface below 450℃, widely adopted in the following industrial equipment:

• Coal-fired thermal power station boiler: Horizontal & vertical economizer tube bundle, low temperature secondary superheater, air preheater tubes
• Circulating fluidized bed CFB boiler: Tail flue low temperature heating surface heat exchange tubing
• Biomass & waste incineration boiler: Medium temperature economizer heat transfer tube bundle
• Industrial chemical waste heat boiler: Medium temperature flue heat recovery heat exchanger
• Shell & tube heat exchanger: Condenser, cooler, oil & water heat exchange equipment tubing

Temperature limit reminder: Do not use ASME SA179 tubes for high temperature superheater above 450℃, select ASME SA210 A1 or alloy steel tubes such as SA213 T12 for high temperature zones.

Performance Comparison: ASME SA179 VS ASME SA210 Grade A1

Field Processing, Welding & Daily Maintenance Guidelines

ASME SA179 low carbon steel tube features excellent weldability, follow standardized operation to avoid tube body damage during boiler overhaul installation:

1. Cutting: Use cold saw cutting only; plasma cutting is forbidden to prevent local overheating hardening of tube end material.

2. Welding: Ordinary carbon steel welding rod can be adopted, preheating is not required for wall thickness ≤4mm thin wall tubes; for wall thickness above 4mm, preheat to 80~150℃ before welding to eliminate welding stress.

3. Tube bundle assembly: Match corresponding size tube shield and snap rings to protect tube outer wall from ash particle abrasion in flue scouring zone.

4. Overhaul inspection: Check tube wall thinning thickness and surface corrosion degree during annual boiler shutdown, replace severely thinned tubes to avoid steam leakage accident.

5. Storage protection: Seal pipe ends with plastic caps to prevent rust and foreign sundries entering tube inner cavity during long-term stock storage.

Optimized Cold Drawn Precision Tube Design Merits

The cold drawn forming process is specially developed for heat exchange equipment with strict heat conduction and dimensional matching requirements:

1. Uniform wall thickness tolerance ensures consistent heat transfer efficiency of each tube in the whole tube bundle, avoid local overheating caused by uneven wall thickness.

2. Smooth inner surface without oxide scale reduces fluid flow resistance, improve boiler heat exchange efficiency and save system energy consumption.

3. Accurate outer diameter size perfectly matches fin stamping processing, no clearance gap between fin and tube outer wall to guarantee heat transfer conduction effect.

4. Normalized low carbon matrix retains high ductility, suitable for on-site cold bending of small radius tube layout in narrow boiler flue space.

Full Batch Factory Inspection Items Comply With ASME SA179

• Raw billet spectral composition test: Strictly control C/Mn/S/P/Si element within SA179 specified limit range
• Post-normalizing mechanical sampling test: Tensile, elongation and flare test to meet minimum mechanical index
• 100% full length eddy current non-destructive flaw detection: Eliminate internal crack, inclusion and drawing defect
• 100% hydrostatic pressure tightness test: Hold pressure without leakage according to ASME standard pressure value
• Full dimensional inspection: Outer diameter, wall thickness, total length and pipe end flatness calibration for each finished tube
• Surface visual full inspection: Remove tubes with scratch, pit, oxide scale and cold drawing indent defects
• Complete MTR material test report issuing: Record each production batch inspection data for overseas project acceptance

Project-oriented Customized ASME SA179 Tubing OEM Solution

We provide personalized tube customization service according to customer boiler heating surface construction drawings and heat exchange design parameters:

Customizable parameters: Special outer diameter, thin / thick wall thickness, fixed single length, pipe end groove processing, fin pre-welding finished tube bundle.

Optional surface anti-rust treatment: Oil coating, transparent anti-rust varnish or plastic cap sealing for long-term warehouse stock.

Additional supporting technical service: Boiler heating surface layout technical consultation, on-site welding construction guidance, long-term bulk spare tube supply framework contract for power plant annual overhaul.

Export Anti-rust Packaging & Global Transportation Specification

ASME SA179 seamless heat transfer tubes adopt anti-rust layered packaging to avoid scratch and rust during cross-border sea and land long-distance transportation:

Single tube coated with thin anti-rust oil, both ends sealed with plastic protective caps; small size tubes bundled with steel strips, wrapped with waterproof plastic film outside each bundle.

Small batch short-length finished tubes packed into fumigated export wooden cases; large bulk long tubes fixed on standard steel pallets with binding belts, marked with size, standard and batch number label on each bundle.

Support FOB, CFR, CIF international trade terms, sea freight and land truck transportation available. Each shipment attached complete MTR material test certificates, non-destructive testing records and dimensional inspection reports for overseas power plant customs clearance and equipment acceptance.