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ASME SA178 Carbon Steel Tubes Supplier: SA178A Boiler Tubes

ERW Boiler Tubes to ASME SA178 Grade A, C & D

Dinesh Tube India supplies ASME SA178 carbon steel tubes (ASTM A178) from Mumbai to boiler makers, power plants and maintenance contractors in India and overseas. SA178 is an electric-resistance-welded (ERW) carbon steel boiler tube, heat treated after welding, made in three grades. The most widely used is SA178 Grade A (SA178A), a low-carbon grade. Grade C and Grade D are higher-strength grades.

We supply SA178 tubes from 12.7 mm to 127 mm OD with an EN 10204 3.1 mill test certificate. Send your grade, OD, minimum wall, length and quantity for a quote.


Table of Contents


What Is SA178A Material?

SA178A material (SA-178A, or ASTM A178 Grade A) is the low-carbon grade of ASME SA178 / ASTM A178/A178M, the standard specification for electric-resistance-welded carbon steel and carbon-manganese steel boiler and superheater tubes. The specification covers boiler tubes, boiler flues, superheater flues and safe ends in sizes from 1/2 in. to 5 in. (12.7 to 127 mm) OD and 0.9 to 9.1 mm minimum wall. General requirements for tolerances, testing and marking come from ASTM A450/A450M.

Grade A has 0.06–0.18% carbon, the same carbon range as seamless SA192 boiler tubes, so it is soft, ductile and easy to expand, bend and weld in the boiler shop. All SA178 tubes are heat treated after welding, which normalises the weld zone. Where more strength is needed, designers use SA178 Grade C (medium carbon) or Grade D (carbon-manganese).

ASME SA178 Grade A ERW carbon steel boiler tubes

Full specification sheet: Download ASTM A178 Tube Material Specification (PDF)


SA178 Tube Specification

Standard

ASTM A178/A178M, ASME SA178/SA178M

Grades

Grade A (SA178A), Grade C, Grade D

Outside Diameter

12.7 mm – 127 mm (1/2" – 5")

Wall Thickness

0.9 mm – 9.1 mm (minimum wall)

Manufacturing Process

Electric-resistance welded (ERW), no filler metal

Heat Treatment

Heat treated after welding

Length

Single random, double random, cut length as required

Ends

Plain end, square cut; bevelled on request

Certification

EN 10204 3.1 MTC; IBR and third-party inspection on request

Value-Added Services

Cutting to length, eddy current testing, hydro testing
SA178 tube specification

SA178 Grade A, C & D Chemical Composition (%)

GradeCarbon (C)Manganese (Mn)Phosphorus (P)Sulphur (S)Silicon (Si)
SA178 Grade A0.06 – 0.180.27 – 0.630.035 max0.035 max—
SA178 Grade C0.35 max0.80 max0.035 max0.035 max—
SA178 Grade D0.27 max1.00 – 1.500.030 max0.015 max0.10 min

SA178 Mechanical Properties

GradeTensile Strength (min)Yield Strength (min)Elongation in 50 mm (min)
SA178 Grade ANo tensile requirements in ASTM A178. Ductility is checked by flattening, flange and reverse flattening tests.
SA178 Grade C415 MPa (60 ksi)255 MPa (37 ksi)30%
SA178 Grade D485 MPa (70 ksi)275 MPa (40 ksi)30%

Many supplier pages list 325 MPa / 180 MPa for SA178A. Those values come from SA179 and are not requirements of A178 Grade A.

Heat Treatment & Testing

All SA178 tubes are heat treated after welding and then cooled, which normalises the weld zone so it matches the parent metal. Tubes are then tested as required by ASTM A178 and A450:

  •   Flattening test: checks ductility of tube and weld
  •   Reverse flattening test: opens the weld line to check fusion
  •   Flange test: tube end flanged without cracking
  •   Tension test: Grades C and D
  •   Hydrostatic or eddy current test: every tube, per A450
  •   Crush test: when specified by the purchaser
Tube ODHydrostatic Test Pressure (max)
Under 25.4 mm (1")7 MPa (1,000 psi)
25.4 – under 38.1 mm (1" – 1½")10 MPa (1,500 psi)
38.1 – under 50.8 mm (1½" – 2")14 MPa (2,000 psi)
50.8 – under 76.2 mm (2" – 3")17 MPa (2,500 psi)
76.2 – 127 mm (3" – 5")24 MPa (3,500 psi)

Test pressure is calculated as P = 32,000 t/D (psi), limited to the maximums above.

SA178 Dimensional Tolerances (ASTM A450)

Outside DiameterOD Tolerance
Under 25.4 mm (1")± 0.10 mm
25.4 – 38.1 mm (1" – 1½")± 0.15 mm
Over 38.1 – under 50.8 mm (1½" – 2")± 0.20 mm
50.8 – under 63.5 mm (2" – 2½")± 0.25 mm
63.5 – under 76.2 mm (2½" – 3")± 0.30 mm
76.2 – 101.6 mm (3" – 4")± 0.38 mm
Over 101.6 – 127 mm (4" – 5")+0.38 / −0.64 mm

Wall thickness for welded tubes ordered to minimum wall: +18% / −0.

SA178 Tube Sizes

Typical boiler tube sizes are listed below. Any OD from 12.7 to 127 mm and minimum wall from 0.9 to 9.1 mm can be quoted on request.

OD (mm)OD (inch)Typical Wall Thickness (mm)
25.41"2.0 – 3.2
31.81¼"2.3 – 3.6
38.11½"2.6 – 4.0
44.51¾"2.6 – 4.5
50.82"2.9 – 5.0
57.12¼"3.2 – 5.0
63.52½"3.2 – 5.6
76.23"3.6 – 6.3
88.93½"4.0 – 7.1
101.64"4.5 – 8.0
114.34½"5.0 – 8.8
127.05"5.6 – 9.1

SA178A Equivalent Material

StandardSA178 Grade ASA178 Grade C
EN 10217-2 (welded)P235GHP265GH
JIS G3461 (Japan)STB 340 (ERW)STB 410 (ERW)
Seamless alternative (ASME)SA192SA210 A1

These are the closest comparable grades, not exact equivalents. Check your design code before substituting one for another.

Need SA178 Grade A, C or D boiler tubes? Send the grade, OD, minimum wall, length and quantity to kamlesh@dineshtube-india.com or call +91 83559 10913. You can also send an enquiry.

Types of SA178 Tubes

SA178A carbon steel boiler tubes

SA178 Boiler Tubes

Grade A, C or D ERW tubes for water walls, economisers and fire-tube boilers. See all boiler tubes.
SA178 superheater flues and safe ends

SA178 Flues & Safe Ends

Boiler flues, superheater flues and safe ends, made and tested to ASME SA178.
SA178 Grade C and Grade D ERW tubes

SA178 Grade C & D Tubes

Higher-strength ERW grades, 415 and 485 MPa minimum tensile, for thinner-wall designs.

SA178 vs SA192, SA210 & SA214

GradeProcessOD RangeMain Use
SA178 A / C / DERW (welded)1/2" – 5"Boiler tubes, flues, safe ends
SA192Seamless, low carbon1/2" – 7"High-pressure boiler tubes
SA210 A1 / CSeamless, medium carbon1/2" – 5"Boiler & superheater tubes
SA214ERW (welded)Up to 3"Heat exchangers & condensers
SA179Seamless, cold drawn1/8" – 3"Heat exchangers & condensers

SA178 Tube Applications

  •   Water-tube boilers and water-wall panels
  •   Fire-tube (smoke-tube) boilers
  •   Economisers and air preheaters
  •   Boiler flues, superheater flues and safe ends
  •   Heat recovery steam generators (HRSG)
  •   Sugar mills and distilleries
  •   Paper mills and process steam boilers
  •   Captive and industrial power plants
Industries using SA178 boiler tubes

Need IBR-certified tubes or another grade? See our IBR tubes, air preheater tubes, products for the boiler industry or all carbon steel tubes.

SA178A Material: FAQs

What is SA178A material?

SA178A (also written SA-178A or SA178 Grade A) is a low-carbon steel tube material to ASME SA178 / ASTM A178 Grade A. It is electric-resistance welded (ERW) and heat treated after welding, with 0.06–0.18% carbon and 0.27–0.63% manganese. SA178A tubes are used as boiler tubes, boiler flues, superheater flues and safe ends, in sizes from 1/2 to 5 in. (12.7 to 127 mm) OD.

Is SA178 tube seamless or welded?

SA178 tubes are always welded, made by electric-resistance welding without filler metal and then heat treated. For a seamless carbon steel boiler tube, specify ASME SA192 (low carbon) or SA210 (medium carbon) instead.

What is the difference between SA178 Grade A, Grade C and Grade D?

Grade A is a low-carbon steel (0.06–0.18% C) for general boiler tubes; the standard does not set tensile requirements for it. Grade C is a medium-carbon steel (0.35% C max) with 415 MPa minimum tensile strength. Grade D is a carbon-manganese steel (1.00–1.50% Mn, 0.10% Si min) with the highest strength, 485 MPa minimum tensile. Higher-strength grades allow a thinner wall for the same pressure.

What is the difference between SA178 and SA192?

Both are carbon steel boiler tubes. SA178 is electric-resistance welded and covers Grades A, C and D up to 5 in. OD. SA192 is seamless low-carbon tube for high-pressure service up to 7 in. OD. SA178 is generally lower in cost; SA192 is chosen where the design code or client requires seamless tube.

What is the difference between SA178 and SA214?

Both are ERW carbon steel tubes, but they are made for different equipment. SA178 is for boiler tubes, flues and safe ends, while SA214 is for heat exchangers and condensers up to 3 in. OD.

What is the equivalent of SA178A?

There is no exact equivalent, but the closest comparable welded grades are EN 10217-2 P235GH and JIS G3461 STB 340 (ERW) for Grade A, and JIS G3461 STB 410 (ERW) for Grade C. Check your design code before substituting, because test and heat-treatment requirements differ between standards.

Export Destinations for SA178 Tubes

We export SA178 boiler tubes to the Middle East (UAE, Saudi Arabia, Qatar, Kuwait, Oman, Bahrain, Iraq, Jordan), Africa (Nigeria, Egypt, South Africa, Kenya, Ghana, Algeria, Morocco, Tunisia), Asia (Japan, South Korea, Singapore, Malaysia, Indonesia, Thailand, Vietnam, Philippines, Bangladesh, Sri Lanka), Europe (Italy, Spain, Portugal, France, Netherlands, Belgium, Poland, Romania, Turkey, United Kingdom), and the Americas (United States, Canada, Mexico, Brazil, Chile, Peru, Colombia, Argentina).