ASTM A213 TP321 Bright Annealed Heat Exchanger Tubes

Gnee Steel (Tianjin) Co., Ltd. is one of the most professional manufacturers and suppliers of ASTM A213 TP321 Bright Annealed Heat Exchanger Tubes in China. With abundant experience, we warmly welcome you to wholesale customized ASTM A213 TP321 Bright Annealed Heat Exchanger Tubes from our factory. For price consultation, contact us.

 

What is SA213 TP321 material?

ASTM A213 TP321 bright-annealed heat exchanger tubing is a titanium-stabilized austenitic stainless steel seamless tube. Designed specifically for high-temperature service (427–816°C), the addition of titanium prevents intergranular corrosion. The bright annealing process, conducted in a controlled atmosphere, ensures a scale-free surface and excellent corrosion resistance, thereby minimizing fouling.

 

Manufacturer of ASTM A213 TP321 Bright Annealed Tubes

GNEE has specialized in the manufacturing and exporting of stainless steel pipes and tubes for over 18 years, serving customers in more than 80 countries across industries such as oil & gas, petrochemicals, power generation, food processing, and heat exchangers.

 

 

Our TP321 bright annealed (BA) heat exchanger tubes are strictly manufactured in accordance with the ASTM A213/ASME SA213 standards, and are supplied with EN 10204 3.1 Material Test Certificates (MTC). Upon customer request, we can arrange for third-party inspection (TPI) by SGS, BV, TÜV, or other internationally recognized agencies to ensure full material traceability and quality assurance.

The TP321 bright annealed tubes we supply undergo precise cold drawing, after which the tubes are subjected to solution annealing in a protective atmosphere of hydrogen or inert gas. This process prevents oxidation and eliminates surface scale, achieving a surface roughness of Ra ≤ 0.8 μm (lower roughness can also be provided upon request). This ultra-smooth surface helps reduce fluid resistance, minimize fouling, and enhance cleanability for high-purity heat exchanger systems. Compared to conventional TP321 annealed and pickled (AP) tubes, the BA surface not only offers a more aesthetically pleasing finish but also delivers superior corrosion resistance.

Furthermore, every single TP321 tube is solution annealed to restore its austenitic microstructure and achieve a typical hardness of ≤192 HB. This heat treatment significantly enhances the material's ductility, facilitating smooth bending and fabrication while minimizing the risk of cracking during welding or tube expanding (roller expanding). Consequently, it ensures reliable operation at continuous service temperatures up to 870°C and provides intermittent oxidation resistance up to 925°C.

 

In addition to straight seamless tubes, GNEE offers U-bend heat exchanger tubes, precision cut-to-length tubes, coiled tubing, as well as customized dimensions, tighter tolerances, and export-grade packaging services.

ASTM A213 TP321 Heat Exchanger Tubes Specification

ASTM A213 SS 321 shell tube heat exchanger  Equivalent

Grade	UNS No	Old British		Euronorm		Swedish SS	Japanese JIS
		BS	En	No	Name
321	S32100	321S31	58B, 58C	1.4541	X6CrNiTi18-10	2337	SUS 321

 

TP321 Chemical Composition(%)

Element	C	Si	Cr	Mn	P	Ni	Ti
Range	≤0.080	≤0.75	17.00-20.00	≤2.00	≤ 0.045	9.00-13.00	≥5*C

 

TP321 Mechanical Properties

Tensile Strength	Yield Strength	Hardness	Elongation
515MPa	≥205MPa	≤ 192HB	≥40%

 

ASTM A213 Tube Tolerances

Specification	Allowable Outside Diameter Variation in mm			Allowable Wall Thickness Variation		Exact Length Tolerance in mm		Testing
	Nominal Diameter	Over	Under	%Over	%Under	Over	Under
ASTM-A213 TP321 Seamless Boiler Superheater and Heat Exchanger Tubes	Under 25.4	.1016	.1016	+20	-0	3.175	0	Flattening Test
	25.4-38.1 incl	.1524	.1524	+22	-0	3.175	0	Tension Test
	38.1-50.8 excl	.2032	.2032	+22	-0	3.176	0	Flare Test
	50.8-63.5 excl	.254	.254	+2	-0	4.46	0	Hardness Test
	63.5-76.2 excl	.3218	.3218	+22	-0	4.76	0	100% Hydrostatic test
	76.2-101.6 incl	.381	.381	+22	-0	4.76	0	Refer to ASTM A-450

 

Temperature Range of UNS S32100 Round Tubes

Properties (MPa)		Temperature Range
		600 °C	700 °C	800°C
Creep resistance	Rz/1000	200	88	30
	Rz/10000	142	48	15
	Rz/100000	65	22	10
Creep limit	R1/1000	110	45	15
	R1/10000	85	30	10

 

ASTM A213 TP321 Tubing Weight Chart

Dimension		18 SWG	10 SWG	19 SWG	14 SWG	16 SWG	12 SWG
		(1.2 MM)	(3.2 MM)	(1.0 MM)	(2.1 MM)	(1.65 MM)	(2.6 MM)
OD	Size	WeighMTR	WeightMTR	WeightMTR	WeighYMTR	WeightMTR	WeighMTR
88.9	31/2"	2.610	6.802	2.180	4.521	3.571	5.566
50.8	2"	1.476	3.778	1.235	2.537	2.012	3.108
12.7	1/2"	0.342	0.754	0.290	0.552	0.452	0.651
19.05	3/4"	0.531	1.258	0.448	0.883	0712	4.061
31.75	11/4"	0.909	2.266	0.763	1.544	1.232	1.880
25.4	1"	0.720	1.762	0.605	1.214	0.972	1.470
15.875	5/8"	0.437	1.006	0.369	0.718	0.582	0.856
38.1	11/2"	1.098	2770	0.920	1.875	1.492	2.289
63.5	21/2"	1.854	4.786	1.550	3.198	2.531	3.928
76.2	3"	2.232	5.794	1.865	3.860	3.051	4747
101.6	4"	2.988	7.810	2.495	5.183	4.091	6.385.

 

If you have any questions regarding the technical specifications, you can download ASTM A213.PDF or contact us!

 

ASTM A213 TP321 Stainless Steel Tube Industry application

Power Plant Boilers: superheater tubes, reheater tubes, and high-temperature, high-pressure steam pipelines

Petrochemical Industry: ethylene cracking furnace tubes, hydrogen conversion furnace tubes, and various high-temperature heat exchangers

Pressure Vessels: Manufacturing container components that withstand high temperatures.

🔹Customer Case Study

Chemical Plant High-Temperature Heat Exchanger Project
The customer used our ASTM A213 TP321 seamless tubes in their high-temperature chemical liquid circulation system. The tubes operated continuously for one year at temperatures exceeding 200°C and remained intact and corrosion-free.

 

🔹Customer Feedback

"The TP321 seamless tubes are perfectly suited for our high-temperature heat exchanger application. Installation was quick and operation has been stable, and it passed third-party inspection successfully."
- Purchasing Manager, Food Processing Equipment Manufacturer

 

 

Quality Inspection

GNEE offers intergranular corrosion (IGC) testing in accordance with ASTM A262 (using Practice E or an equivalent method specified by the customer) to verify the material's resistance to sensitization and intergranular corrosion following heat treatment or welding. Additional quality assurance services include PMI (Positive Material Identification), eddy current testing, hydrostatic testing, ultrasonic testing, underwater air-under-water testing, flattening tests, flaring tests, tensile tests, hardness tests, surface roughness measurements, and 100% visual inspection.

High-Quality Packaging

End Caps: Plastic caps must be fitted to prevent dust and moisture from entering the pipes during transport.
Packaging: Plywood crates are typically required; plastic film or soft paper must be placed between the pipes to prevent friction and scratching.

 

FAQ 

What precautions should be taken when welding TP321 tubing?
ER321 or ER347 filler wire is typically used. High-purity argon gas is essential for back purging; otherwise, the inner wall of the BA tubing will oxidize, causing it to lose the advantages of the BA finish.

 

Why is "stabilizing annealing" sometimes required for TP321 pipes?
In addition to standard solution annealing, some customers require a stabilizing heat treatment at 845°C–900°C. This ensures that the titanium fully combines with the carbon, providing maximum protection in extremely harsh, high-temperature corrosive environments.

 

What is the difference between TP321 and TP347 (niobium-stabilized)?
TP321 uses titanium (Ti), while TP347 uses niobium (Nb). TP347 offers slightly better stability than TP321 at extremely high temperatures (above 800°C) and superior corrosion resistance in certain strongly oxidizing media (such as nitric acid). TP321 is generally more cost-effective than TP347, making it the preferred choice for most heat exchangers operating in the 400–800°C range.

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