Seamless Pipes for High-Temperature Applications are engineered to perform reliably under extreme heat, making them essential for industries like power generation, petrochemicals, and refineries. These high-temperature seamless tubes comply with standards such as ASTM A335, ASME SA335, and EN 10216-2, offering exceptional strength, creep resistance, and corrosion resistance for applications like boilers, superheaters, and heat exchangers operating at temperatures up to 650°C.

Crafted from high-quality alloy steel (e.g., P5, P9, P11, P22) or stainless steel (e.g., 310S), alloy steel high-temperature pipes are produced through hot-rolling or cold-drawing processes to ensure precise dimensions and a smooth surface finish. Available in sizes from 1/8” to 24” (DN6–DN600) with wall thicknesses from SCH 40 to SCH 160, these pipes are designed to withstand high-pressure steam, gases, and fluids in extreme thermal conditions. Their seamless construction eliminates weld-related weaknesses, ensuring durability in demanding environments.

Chrome moly seamless pipes undergo stringent testing, including tensile, creep, hardness, and non-destructive tests (e.g., ultrasonic, eddy current), to ensure compliance with industry standards. With tensile strengths ranging from 415 MPa (P11) to 655 MPa (P22), these pipes resist thermal fatigue, oxidation, and creep deformation. Surface treatments like varnishing, 3LPE, or FBE coatings enhance corrosion resistance, making them suitable for handling corrosive fluids or operating in acidic environments.

Compared to welded pipes, heat-resistant piping offers superior integrity and uniform strength, reducing the risk of failures under high temperatures and pressures. These pipes are customizable for specific applications, such as steam pipelines, furnace tubes, or superheater tubes, meeting tight dimensional tolerances. Their ability to withstand thermal cycling and high-temperature corrosion makes them ideal for long-term use in critical systems like power boilers and petrochemical reactors.

By addressing challenges like thermal stress, oxidation, and creep, seamless boiler tubes ensure safe and efficient operation in high-temperature applications. Their robust design and material properties make them a reliable choice for engineers seeking durable solutions for extreme heat environments, delivering unmatched performance and longevity.

What are High-Temperature Service Seamless Tubes?

Designed for 400 °C to 1100 °C service—commonly known as heat exchanger tubes—these tubes include two primary types:

High‑Temperature Carbon Steel Tubes

ASTM A179, A192, A210 (ASME SA179, SA192, SA210) specify seamless carbon steel tubes for heat exchangers and condensers. For high‑temperature service above ~400 °C, material should comply with ASTM A530 when required.

High‑Temperature Alloy Steel Tubes (Chrome‑Moly)

ASTM A213 and A209 (ASME SA213 / SA209) cover seamless alloy steel tubes suitable for boiler, superheater, and heat exchanger circuits. Typical grades include T5, T9, T11, T12, T22, T91 etc., classified as chrome‑molybdenum steels.

Chemical Composition of ASTM A335 P9, P11, and 310S Stainless Steel
Grade	C (% max)	Si (% max)	Mn (% max)	P (% max)	S (% max)	Cr (%)	Mo (%)	Ni (%)
ASTM A335 P9	0.15	0.25–1.00	0.30–0.60	0.025	0.025	8.00–10.00	0.90–1.10	-
ASTM A335 P11	0.15	0.50–1.00	0.30–0.60	0.025	0.025	1.00–1.50	0.44–0.65	-
310S SS	0.08	1.50	2.00	0.045	0.030	24.0–26.0	-	19.0–22.0

The chemical composition ensures high-temperature strength, creep resistance, and corrosion resistance for extreme conditions.

Mechanical Properties of ASTM A335 P9, P11, and 310S Stainless Steel
Grade	Tensile Strength (MPa min)	Yield Strength (MPa min)	Elongation (% min)	Hardness (HB max)
ASTM A335 P9	415	205	30	163
ASTM A335 P11	415	205	30	163
310S SS	515	205	40	217

These properties ensure durability, thermal fatigue resistance, and reliability in high-temperature environments.

Seamless pipes for high-temperature applications are weld-free pipes designed to handle extreme heat and pressure in industries like power generation and petrochemicals.

Common materials include alloy steel (P5, P9, P11, P22) and stainless steel (310S) for high-temperature and corrosion resistance.

- ASTM A335 P9: C ≤0.15%, Cr 8.00–10.00%, Mo 0.90–1.10%
- ASTM A335 P11: C ≤0.15%, Cr 1.00–1.50%, Mo 0.44–0.65%
- 310S SS: C ≤0.08%, Cr 24.0–26.0%, Ni 19.0–22.0%

- ASTM A335 P9: Tensile ≥415 MPa, Yield ≥205 MPa, Elongation ≥30%
- ASTM A335 P11: Tensile ≥415 MPa, Yield ≥205 MPa, Elongation ≥30%
- 310S SS: Tensile ≥515 MPa, Yield ≥205 MPa, Elongation ≥40%

Sizes range from 1/8” to 24” (DN6–DN600), with wall thicknesses from SCH 40 to SCH 160, customizable for specific applications.

Tensile, creep, hardness, ultrasonic, and eddy current tests ensure compliance with ASTM and EN standards.

Boilers, superheaters, heat exchangers, petrochemical reactors, refineries, and furnace tubes.

Alloy steel and stainless steel grades, combined with coatings, resist oxidation, creep, and thermal fatigue up to 650°C.

Seamless pipes offer uniform strength and no weld seams, reducing the risk of failures under high heat and pressure.

Yes, coatings like 3LPE or FBE and high-alloy materials like 310S SS ensure corrosion resistance in acidic or high-temperature conditions.

Technical Specifications

Explore the dimensional ranges and common applications of various seamless pipe types.

Typical dimensional ranges for seamless steel pipe types
Type	Outer Diameter	Wall Thickness	Length	Applications
Hot-Rolled Seamless	Above 32 mm	2.5 – 200 mm	Up to 12 m	General industrial, structural
Cold-Rolled Seamless	6 – 650 mm	0.25 – 50 mm	Up to 12 m	Precision applications
Thin-Walled Pipe	5 – 100 mm	Less than 0.25 mm	Up to 6 m	Instrumentation, automotive
Heavy Wall Pipe	50 – 650 mm	10 – 200 mm	Up to 12 m	High pressure, structural

Seamless Pipe Specification Chart
DN	NB (inch)	OD (mm)	Nominal Wall Thickness (mm)
DN	NB (inch)	OD (mm)	SCH10	SCH20	SCH30	STD	SCH40	SCH60	XS	SCH80	SCH100	SCH120	SCH140	SCH160	XXS
15	1/2"	21.3	2.11		2.41	2.77	2.77		3.73	3.73				4.78	7.47
20	3/4"	26.7	2.11		2.41	2.87	2.87		3.91	3.91				5.56	7.82
25	1"	33.4	2.77		2.90	3.38	3.38		4.55	4.55				6.35	9.09
32	1.1/4"	42.2	2.77		2.97	3.56	3.56		4.85	4.85				6.35	9.70
40	1.1/2"	48.3	2.77		3.18	3.68	3.68		5.08	5.08				7.14	10.15
50	2"	60.3	2.77		3.18	3.91	3.91		5.54	5.54				8.74	11.07
65	2.1/2"	73	3.05		4.78	5.16	5.16		7.01	7.01				9.53	14.02
80	3"	88.9	3.05		4.78	5.49	5.49		7.62	7.62				11.13	15.25
90	3.1/2"	101.6	3.05		4.78	5.74	5.74		8.08	8.08
100	4"	114.3	3.05		4.78	6.02	6.02		8.56	8.56				13.49	17.12
125	5"	141.3	3.4			6.55	6.55		9.53	9.53		12.7		15.88	19.05
150	6"	168.3	3.4			7.11	7.11		10.97	10.97		14.27		18.26	21.95
200	8"	219.1	3.76	6.35	7.04	8.18	8.18	10.31	12.7	12.7	15.09	18.26	20.62	23.01	22.23
250	10"	273	4.19	6.35	7.8	9.27	9.27	12.7	12.7	15.09	18.26	21.44	25.4	28.58	25.4
300	12"	323.8	4.57	6.35	8.38	9.53	10.31	14.27	12.7	17.48	21.44	25.4	28.58	33.32	25.4
350	14"	355.6	6.35	7.92	9.53	9.53	11.13	15.09	12.7	19.05	23.83	27.79	31.75	35.71
400	16"	406.4	6.35	7.92	9.53	9.53	12.7	16.66	12.7	21.44	26.19	30.96	36.53	40.19
450	18"	457.2	6.35	7.92	11.13	9.53	14.27	19.05	12.7	23.83	39.36	34.93	39.67	45.24
500	20"	508	6.35	9.53	12.7	9.53	15.09	20.62	12.7	26.19	32.54	38.1	44.45	50.01
550	22"	558.8	6.35	9.53	12.7	9.53		22.23	12.7	28.58	34.93	41.28	47.63	53.98
600	24"	609.6	6.35	9.53	14.27	9.53	17.48	24.61	12.7	30.96	38.89	46.02	52.37	59.54
650	26"	660.4	7.92	12.7		9.53			12.7
700	28"	711.2	7.92	12.7	15.88	9.53			12.7
750	30"	762	7.92	12.7	15.88	9.53			12.7
800	32"	812.8	7.92	12.7	15.88	9.53	17.48		12.7
850	34"	863.6	7.92	12.7	15.88	9.53	17.48		12.7
900	36"	914.4	7.92	12.7	15.88	9.53	19.05		12.7

Seamless Pipes

Minimum Thickness

Seamless pipes, available in various wall thicknesses, are designed for precise applications, with cold-rolled thin-walled pipes achieving thicknesses as low as 0.25 mm or less.

The outer diameter of hot-rolled seamless pipe is generally greater than 32mm, the wall thickness is 2.5-200mm, the outer diameter of cold-rolled seamless steel pipe can be 6mm, the wall thickness can be 0.25mm, the outer diameter of thin-walled pipe can be 5mm, and the wall thickness is less than 0.25mm, cold rolling

The ability to produce seamless pipes with ultra-thin walls and controlled ovality makes them critical for industries like automotive, hydraulics, and petrochemicals, ensuring reliability and performance.

Permissible Variations in Outside Diameter of Steel Pipes
NPS/ DN/ OD	Permissible Variations in Outside Diameter
	Over		Under
	in.	mm	in.	mm
NPS 1/8 to 1½, incl DN 6 to 40 OD 10.3 to 48.3, mm	1/64	0.4	1/64	0.4
Over 1½ to 4, incl DN 40 to 100 OD 48.3 to 114.3, mm	1/32	0.8	1/32	0.8
Over 4 to 8, incl DN 100 to 200 OD 114.3 to 219.1, mm	1/16	1.6	1/32	0.8
Over 8 to 18, incl DN 200 to 450 OD 219.1 to 457, mm	3/32	2.4	1/32	0.8
Over 18 to 26, incl DN 450 to 650 OD 457 to 660, mm	1/8	3.2	1/32	0.8

According to the production method, seamless tubes are divided into hot - rolled tubes, cold - rolled tubes, cold - drawn tubes, extruded tubes, jacking tubes, etc. The maximum diameter is 650 mm and the minimum diameter is 0.3 mm. Depending on the application, there are thick - walled tubes and thin - walled tubes. Seamless steel tubes are mainly used as petroleum geological drilling tubes, cracking tubes for petrochemical industry, boiler tubes, bearing tubes and high - precision structural steel tubes for automobiles, tractors and aviation. In the plate, Q345B seamless steel pipe belongs to the low - alloy series.

Among the low - alloy materials, this kind of material is the most common. The outside diameter of hot - rolled seamless pipe is usually more than 32mm, the wall thickness is 2.5 - 200mm, the outside diameter of cold - rolled seamless steel pipe can be 6mm, the wall thickness can be 0.25mm, the outside diameter of thin - walled pipe can be 5mm, and the wall thickness is less than 0.25mm, cold rolling has higher dimensional accuracy than hot rolling.

Common Standards for Seamless Pipes

A consolidated overview of international seamless pipe standards, their materials, and applications.

Overview of Seamless Pipe Standards from ASTM, API, JIS, and GB
Standard System	Standard Code	Material Type	Typical Applications
ASTM / ASME (USA)	ASTM A53	Carbon Steel	General-purpose piping, structural
	ASTM A106	Carbon Steel	High-temperature service
	ASTM A179	Low Carbon Steel	Heat exchangers, condensers
	ASTM A333	Carbon/Alloy Steel	Low-temperature service
	ASTM A335	Alloy Steel	High-temperature, pressure piping
	ASTM A213 / A209	Alloy/Stainless Steel	Boilers, superheaters
	ASTM A312	Stainless Steel	Corrosion-resistant piping
	ASTM A519	Carbon/Alloy Steel	Mechanical tubing (e.g., SAE 1026)
	ASTM A790	Duplex Stainless Steel	High-strength, corrosion-resistant service
API (Oil & Gas)	API 5L	Carbon Steel	Oil & gas pipelines
API (Oil & Gas)	API 5CT	Carbon Steel	Casing & tubing for wells
JIS (Japan)	JIS G3454/G3455/G3456	Carbon Steel	Pressure piping service
	JIS G3460	Carbon Steel	Boilers, heat exchangers
	JIS G3429	High-strength Steel	High-pressure gas cylinders
GB (China)	GB 3087	Carbon Steel	Low & medium pressure boilers
	GB 5310	Carbon Steel	High-pressure boiler pipes
	GB/T 8163	Carbon Steel	Fluid and structural use

Industry Applications

Seamless pipes are critical in various industries thanks to their excellent strength, temperature resistance, and structural uniformity. They ensure safe and efficient performance in demanding environments.

Power Generation

Used in steam pipelines, boiler tubes, superheaters, and heat exchangers for high-temperature and high-pressure conditions in power plants.

Oil & Gas Industry

Transports crude oil, natural gas, and petroleum products in pipelines and refinery units, handling high-pressure and corrosion.

Chemical & Petrochemical

Handles chemicals, gases, and hazardous substances in reactors and heat exchangers, ensuring safe processing.

Mechanical & Automotive

Applied in automotive systems and machinery for fluid conveyance and precision components requiring strength and accuracy.

Construction & Structural

Used in structural support, water and sewage systems, and building frameworks for strength and corrosion resistance.

Marine & Shipbuilding

Utilized in hydraulic and engine systems onboard, resisting corrosion in marine environments.

Aerospace & Defense

Employed in aircraft and military equipment for hydraulic systems and structural components.

Food & Pharmaceuticals

Stainless pipes for hygienic transport of food and pharmaceutical products, maintaining sterility.

Mining & Slurry Transport

Designed for transporting slurries and chemicals in mining, withstanding abrasion and harsh conditions.

Related products

High Temperature Service Pipe

ASTM A335 P22 Pipe

GB/T 5310

ASTM A335 P91 Pipe

ASTM A335 P92 Pipe

ASTM A335 P9 Pipe

High-Pressure Boiler Tubes