ASTM A106 Grade B Seamless Pipe for High Temperature

The ASTM A106 standard is designed for high-temperature use, and this is why it requires fully-killed steel with a minimum of 0.10% silicon. Deoxidation ensures that the pipe remains sound even when hot water and steam pipes are operating over long periods of time. Very few specifications omit this requirement. The ASTM A106 Grade B has a yield strength of 240 MPa and tensile strength of 415 MPa, and it readily bends, flanges or welds on the job. The ASTM Steel A106 Grade B is the standard carbon steel process pipe in any kind of industry all the way from refineries to power plants and processing plants in Oman. Related grades sit on the carbon steel seamless pipes and tubes hub.

A106 Grade B Applications in Gulf Plants

Refining and petrochemicals: process, steam, condensate and hot oil lines
Power and water: steam, feedwater and auxiliary piping in power and desalination plants
Gas processing and LNG: hot process and utility lines (low-temperature lines use A333)
Upstream facilities: plant piping at gathering stations and production facilities
Fertilizer plants: steam and utility systems

Where metal temperature can drop below about -29 °C, including during blowdown, switch to ASTM A333 Grade 6. For general utility and structural pipe, ASTM A53 seamless pipe may be enough.

A106 Grade B in Sour Service

A106 Grade B can be used in sour service under NACE MR0175 / ISO 15156-2 when hardness is held to 22 HRC (250 HV) in the pipe, welds and heat-affected zones. Seamless construction avoids the question of seam hardness altogether, which makes A106 a common sour process pipe. Wet sour service may also call for HIC testing. State your sour service and testing requirements in the RFQ; they are confirmed at quotation. See the NACE MR0175 sour service guide.

What Affects the Price of A106 Grade B Pipe

NPS, schedule and length
Hot finished or cold drawn (small sizes are often cold drawn)
Single, dual or triple certification
Quantity and mill minimums
Stock availability versus a mill order
Supplementary tests: hardness, NDT, PMI or HIC
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, NPS, schedule or wall, length, quantity, end finish, any dual certification, supplementary tests, certification, inspection, destination port and required date.

A106 Mill Certificates and Inspection

A106 Grade B pipe is 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. Check the certificate for silicon (0.10% minimum), the five-element residual total, tensile results and the hydrostatic or NDE test record. See the MTC and EN 10204 certification guide.

Packing A106 Pipe for Gulf Sites

Lead time is confirmed at quotation. Pipe ships with plastic end caps or bevel protectors, varnish on the outside surface where specified, and small sizes in strapped hexagonal bundles. Carbon steel rusts quickly on humid coastal yards, so store pipe on sleepers off the ground, keep caps on until fabrication, and protect bevels from blowing sand. UV-stable caps are worth specifying for long outdoor storage.

Fittings and Flanges for A106 Grade B

Carbon steel buttweld fittings to ASTM A234 WPB
Carbon steel forged fittings to ASTM A105 for socket weld and threaded work
ASTM A105 carbon steel flanges and weld neck flanges
Carbon steel fittings and flanges hub

A106 Grade B is used across refinery and petrochemical, power generation and oil and gas plants.

A106 Grade B Chemical Composition

Element	Grade B (%)
Carbon (C)	0.30 max
Manganese (Mn)	0.29 to 1.06
Phosphorus (P)	0.035 max
Sulphur (S)	0.035 max
Silicon (Si)	0.10 min
Chromium (Cr)	0.40 max
Copper (Cu)	0.40 max
Molybdenum (Mo)	0.15 max
Nickel (Ni)	0.40 max
Vanadium (V)	0.08 max

The five residual elements (Cr, Cu, Mo, Ni and V) must not total more than 1.00%. The standard also allows manganese above 1.06% when carbon is reduced below its maximum, within a set limit.

Worked example: the residual element check

A certificate shows Cr 0.30%, Cu 0.35%, Mo 0.10%, Ni 0.30% and V 0.02%. Every element is individually within its limit. Add them together, though, and the total is 1.07%, which exceeds the 1.00% combined maximum. The heat does not conform to A106. This is one of the easiest checks to miss when reviewing mill certificates, and it matters most on pipe made from scrap-based steel, where residuals tend to run higher.

A106 Grade B Mechanical Properties

Property	Grade A	Grade B	Grade C
Minimum tensile strength	330 MPa (48,000 psi)	415 MPa (60,000 psi)	485 MPa (70,000 psi)
Minimum yield strength	205 MPa (30,000 psi)	240 MPa (35,000 psi)	275 MPa (40,000 psi)
Hardness	Not specified	Not specified	Not specified

Grade B is by far the most commonly supplied. Elongation is calculated from the formula in the standard according to specimen size. Every length is hydrostatically tested or examined by a non-destructive electric test, and bend or flattening tests apply by size. A106 has no impact test requirement, which is why it is not used for low-temperature service.

A106 Grade B Pipe Sizes and Schedules

A106 covers NPS 1/8 to NPS 48, with dimensions to ASME B36.10M.

NPS	DN	OD (mm)	OD (in)	Sch 40 (mm)	Sch 80 (mm)	Sch 160 (mm)	XXS (mm)
1/2	15	21.3	0.840	2.77	3.73	4.78	7.47
3/4	20	26.7	1.050	2.87	3.91	5.56	7.82
1	25	33.4	1.315	3.38	4.55	6.35	9.09
2	50	60.3	2.375	3.91	5.54	8.74	11.07
3	80	88.9	3.500	5.49	7.62	11.13	15.24
4	100	114.3	4.500	6.02	8.56	13.49	17.12
6	150	168.3	6.625	7.11	10.97	18.26	21.95
8	200	219.1	8.625	8.18	12.70	20.62	22.23
10	250	273.1	10.750	9.27	15.09	25.40	25.40
12	300	323.9	12.750	10.31	17.48	33.32	25.40

Wall thickness may run up to 12.5% under nominal, so check the minimum wall against your design. Full tables are in the pipe schedule, NPS and wall thickness guide and pipe weight chart.

Manufacture: seamless, hot finished or cold drawn. Cold drawn pipe is heat treated after the final draw.
Ends: plain, bevelled for welding, or threaded.
Lengths: single random, double random or cut lengths. For sea freight into Sohar, Duqm, Salalah, Jebel Ali or Dammam, 5.8 m and 11.8 m lengths fit 20 ft and 40 ft containers.

Sizes are supplied to specification. Send your NPS, schedule and length.

A106 Equivalents and Dual Certification

Standard	Nearest equivalent to A106 Grade B
ASME	SA-106 Grade B (identical, for ASME code work)
EN 10216-2	P265GH
DIN 17175 (superseded)	St 45.8
JIS G3456	STPT410

The EN, DIN and JIS grades are close but not identical, so check chemistry and testing before substitution.

Seamless pipe is often certified to A106 Grade B, A53 Grade B and API 5L Grade B PSL1 at once. That is valid only if every requirement of each standard is met, including A106's silicon minimum and API 5L's marking. See API 5L Grade B line pipe for the pipeline side.

Operators in the region often add carbon equivalent limits, supplementary hardness testing or PMI. Send your specification with the enquiry.

ASTM A106 Grade B FAQ

What is the difference between A106 Grade B and A53 Grade B?

Both have 240 MPa minimum yield and 415 MPa minimum tensile. A106 requires killed steel with at least 0.10% silicon, tighter phosphorus and sulphur limits, and is intended for high-temperature service. A53 has no silicon minimum and is aimed at general service.

Can A106 Grade B be used for low-temperature service?

Not where metal temperature can drop well below zero. A106 has no impact test requirement. Use ASTM A333 Grade 6, impact tested at -45 °C.

Is SA-106 the same as A106?

Yes. SA-106 is the ASME Boiler and Pressure Vessel Code adoption of ASTM A106, with the same requirements.

What is the residual element limit in A106?

Chromium, copper, molybdenum, nickel and vanadium must not total more than 1.00%, even when each is within its individual limit.

Is A106 Grade B suitable for sour service?

Yes, under NACE MR0175 / ISO 15156-2, when hardness is held to 22 HRC (250 HV) in the pipe and welds. State sour requirements in the RFQ.

What should I send for an A106 quotation?

Send the grade, NPS, schedule or wall, length, quantity, end finish, certification needs, supplementary tests, inspection, destination port and required date.

Request a Quote for ASTM A106 Grade B Seamless Pipe

Send the NPS, schedule, length and quantity, with your piping specification attached if you have one. Every enquiry is checked against ASTM A106 before the offer is prepared, so issues such as a low-temperature line listed in A106 are raised at the start.

Request a Quotation

ASTM A106 Grade B Seamless Pipe for High-Temperature Service