ASTM A179 Heat Exchanger Tubes: Cold Drawn Seamless

In a shell and tube exchanger, a single leaking tube joint among several hundred can take the whole unit offline, so A179 tubes are made to close cold drawn tolerances with a 72 HRB hardness limit to make every tube-to-tubesheet joint roll the same way. Consistency is what buyers pay for. ASTM A179 heat exchanger tubes are low-carbon seamless tubes, cold drawn and heat treated, from 3.2 mm to 76.2 mm OD. They are the most widely specified carbon steel tubes for exchangers, condensers and coolers in refineries, gas plants and power stations across Oman. Boiler tube grades sit on the carbon steel seamless pipes and tubes hub.

Where A179 Tubes Are Used

Shell and tube heat exchangers in refining, petrochemical and gas processing units
Surface condensers and coolers where the cooling medium suits carbon steel
Feedwater heaters in power plants
Air coolers and lube oil coolers on compressors and turbines
Reboilers and preheaters

For seawater or corrosive cooling media, carbon steel is usually not suitable. Copper nickel and titanium tubes or stainless steel tubes are the usual alternatives. The welded equivalent of A179 is ASTM A214.

A179 Chemical Composition

Element	A179 (%)
Carbon (C)	0.06 to 0.18
Manganese (Mn)	0.27 to 0.63
Phosphorus (P)	0.035 max
Sulphur (S)	0.035 max

Low carbon keeps the tube soft and ductile for expansion.

A179 Mechanical Properties

Property	A179
Minimum tensile strength	325 MPa (47,000 psi)
Minimum yield strength	180 MPa (26,000 psi)
Minimum elongation in 50 mm	35%
Maximum hardness	72 HRB

Every A179 tube is cold drawn and then heat treated at 650 °C (1,200 °F) or higher after the final cold draw, which restores ductility. Tubes undergo flattening, flaring and flange tests, plus a hydrostatic or non-destructive electric test on each tube, under the general requirements of ASTM A450.

A179 Tube Sizes and BWG Wall Thickness

A179 covers tubes from 3.2 mm to 76.2 mm OD (1/8 in to 3 in). Exchanger tubes are ordered by OD and wall, most often in BWG gauges and on minimum wall.

OD	BWG 18	BWG 16	BWG 14	BWG 12
15.88 mm (5/8 in)	1.24 mm (0.049 in)	1.65 mm (0.065 in)	2.11 mm (0.083 in)	2.77 mm (0.109 in)
19.05 mm (3/4 in)	1.24 mm (0.049 in)	1.65 mm (0.065 in)	2.11 mm (0.083 in)	2.77 mm (0.109 in)
25.40 mm (1 in)	1.24 mm (0.049 in)	1.65 mm (0.065 in)	2.11 mm (0.083 in)	2.77 mm (0.109 in)
31.75 mm (1-1/4 in)	1.24 mm (0.049 in)	1.65 mm (0.065 in)	2.11 mm (0.083 in)	2.77 mm (0.109 in)
38.10 mm (1-1/2 in)	1.24 mm (0.049 in)	1.65 mm (0.065 in)	2.11 mm (0.083 in)	2.77 mm (0.109 in)

Note that a 3/4 in exchanger tube is 19.05 mm OD, while NPS 3/4 pipe is 26.7 mm OD. OD and wall tolerances follow ASTM A450.

Worked example: tube quantity and bundle weight

An exchanger needs 500 tubes, 19.05 mm OD × 2.11 mm (BWG 14) minimum wall, 6.1 m long. Weight per metre is (19.05 minus 2.11) × 2.11 × 0.02466, which gives 0.881 kg/m. The bundle therefore needs 3,050 m of tube weighing about 2,690 kg, before any allowance for spares. Because tubes are ordered on minimum wall, actual weight will run slightly above this figure, which is worth remembering when planning freight.

Manufacture: seamless, cold drawn, heat treated after final draw
Ends: plain square cut and deburred
Forms: straight lengths or U-bent tubes to the bundle drawing
Lengths: exact cut lengths. For sea freight into Sohar, Duqm, Salalah, Jebel Ali or Dammam, tubes up to 11.8 m fit a 40 ft container.

Sizes are supplied to specification. Send your OD, BWG or minimum wall, length and quantity.

A179 Equivalents

Standard	Nearest equivalent
ASME	SA-179 (identical, for ASME code exchangers)
JIS G3461	STB340
DIN 17175 (superseded)	St 35.8
EN 10216-2	P195GH

These are close, not identical. ASME code exchangers normally require SA-179 on the certificate. TEMA-designed exchangers also set their own tube gauge and tolerance expectations, so include the exchanger specification with the enquiry.

A179 Tubes and Sour Service

In sour process exchangers, tubes must meet NACE MR0175 / ISO 15156-2, with hardness no higher than 22 HRC (250 HV). A179's 72 HRB limit sits far below that, so the steel itself is rarely the issue. What matters is the process side: wet H2S with chlorides or CO2 can corrode carbon steel tubes quickly, and a higher-alloy tube may be the better long-term choice. State any sour requirements in the RFQ; they are confirmed at quotation.

A179 Tube Price Factors

OD, BWG or minimum wall, and length
Straight or U-bent tubes
Quantity and mill minimums
Stock availability versus a mill order
Supplementary tests: eddy current, ultrasonic, hydrostatic
Special packing such as wooden crates
Certification (EN 10204 3.1 or 3.2) and third-party inspection
Incoterm and destination port

Quotations are available in USD, OMR, AED, SAR, QAR, KWD and BHD, on EXW, FOB, CFR or CIF terms.

What to send for a quotation: grade, OD, wall (BWG or mm, minimum or average), length, quantity, straight or U-bent with bend radii, tests, packing, certification, inspection, destination port and required date.

A179 Certificates and Inspection

A179 tubes are supplied with EN 10204 3.1 mill test certificates as standard, and EN 10204 3.2 certificates on request. Inspection by the buyer's nominated third-party agency can be arranged; state your requirement in the RFQ. Certificates show chemistry, tensile and hardness results, flattening, flaring and flange tests, and the hydrostatic or eddy current record for each tube. For U-bent tubes, bend area heat treatment and hydrotest records should also be included where specified. See the MTC and EN 10204 certification guide.

Packing Exchanger Tubes for Gulf Delivery

Lead time is confirmed at quotation. A179 tubes are packed in wooden crates or tightly strapped bundles with end caps, and coated with rust-preventive oil inside and out. Crating protects the thin walls from bending in transit, and U-bent tubes are packed by row to keep bends undamaged. Store tubes indoors on Gulf sites, because coastal humidity rusts carbon steel quickly and any internal corrosion can spoil the tube-to-tubesheet joint.

Related Exchanger and Boiler Tubes

Exchanger tubes join the tube sheet by expansion or welding rather than pipe fittings. Related products:

ASTM A214 welded heat exchanger tubes
ASTM A192 boiler tubes
Stainless steel pipes and tubes for corrosive duty
Copper nickel and titanium pipes and tubes for seawater cooling

A179 is used across refinery and petrochemical, LNG and gas processing, power generation and fertilizer plants.

ASTM A179 Heat Exchanger Tube FAQ

What are the mechanical properties of A179 tubes?

Minimum tensile strength 325 MPa (47,000 psi), minimum yield strength 180 MPa (26,000 psi), minimum elongation 35% in 50 mm, and maximum hardness 72 HRB.

Are A179 tubes seamless?

Yes. A179 tubes are seamless, cold drawn and heat treated after the final draw. The welded equivalent is ASTM A214.

What sizes does A179 cover?

Tubes from 3.2 mm to 76.2 mm OD (1/8 in to 3 in), usually ordered by BWG wall on a minimum wall basis.

Can you supply U-bent A179 tubes?

U-bent tubes can be supplied to the bundle drawing. State the bend radii and any bend heat treatment in the RFQ.

Is A179 suitable for seawater cooling?

Generally not. Carbon steel corrodes quickly in seawater, so copper nickel, titanium or stainless steel tubes are normally used.

What should I send for an A179 quotation?

Send the OD, wall (BWG or mm, minimum or average), length, quantity, straight or U-bent, tests, packing, certification, inspection, destination port and required date.

Request a Quote for ASTM A179 Heat Exchanger Tubes

Send the OD, wall, length and quantity, with the exchanger datasheet or tube schedule attached. Every enquiry is checked against ASTM A179 before the offer is prepared, so a wall given in BWG without a minimum or average basis is clarified at the start.

Request a Quotation

ASTM A179 Cold Drawn Heat Exchanger and Condenser Tubes