ASTM A269 TP304 Stainless Steel Seamless Pipes For Boiler

Why do boiler projects still frequently encounter issues such as uneven wall thickness, severe scaling, or early leakage even when using standard stainless steel pipes? The key often lies in whether the pipe's wall thickness uniformity, internal surface finish, and resistance to intergranular corrosion truly meet the demands of long-term high-temperature operation.

 

Our ASTM A269 TP304 Stainless Steel Seamless Pipes for Boiler are specifically designed for high-temperature steam boilers. The wall thickness of these pipes is strictly controlled, with deviations typically within ±10%, ensuring uniform heat transfer and preventing localized overheating. The internal surface of TP304 pipes is precision-polished, achieving a surface roughness (Ra) typically ≤0.8 μm, which effectively reduces scaling, improves fluid flow, and ensures stable long-term boiler operation.

 

Furthermore, all ASTM A269 TP304 stainless steel seamless pipes undergo standard solution annealing (≥1040°C followed by rapid cooling) to fully dissolve carbides and relieve welding or machining stresses, effectively preventing intergranular corrosion (IGC). By rigorously controlling wall thickness uniformity, internal surface quality, and corrosion resistance, we successfully address common issues in boiler applications, such as localized overheating, excessive scaling, early pipe leakage, and frequent maintenance.

In a real-world case, a chemical plant in Vietnam adopted our high-quality TP304 seamless boiler pipes. As a result, the system's scaling rate decreased by approximately 20%, installation efficiency improved by 30%, and overall service life increased by over 25%, providing the client with safer, more efficient, and lower-maintenance long-term operation.

 

A269 TP304 Stainless Steel Seamless Tube Chemical Composition

SS	304	304N	304LN
Ni	8 – 11	8 – 11	8 – 11
Fe	Balance
Cr	18 – 20	18 – 20	18 – 20
C	0.08 max	0.08 max	0.035 max
Si	0.75 max	0.75 max	0.75 max
Mn	2 max	2 max	2 max
P	0.040 max	0.040 max	0.040 max
S	0.030 max	0.030 max	0.030 max
N		0.10 – 0.16	0.10 – 0.16

 

A269 TP304 Stainless Steel Seamless Tube Mechanical Properties

Density	8.0 g/cm3
Melting Point	1400 °C (2550 °F)
Tensile Strength	Psi – 75000 , MPa – 515
Yield Strength (0.2%Offset)	Psi – 30000 , MPa – 205
Elongation	35%

 

A269 TP304 Stainless Steel Seamless Tube Physical Properties

Grade	Density (kg/m3)	Elastic Modulus (GPa)	Mean Coefficient of Thermal Expansion (m/m/0C)			Thermal Conductivity (W/m.K)		Specific Heat 0-1000C (J/kg.K)	Electrical Resistivity (n.m)
			0-100°C	0-315°C	0-538°C	at 100°C	at 500°C
304/H	8000	193	17.2	17.8	18.4	16.2	21.5	500	720

 

Diameter Tolerance ASTM A269 TP304 Tube

NPS	ASTM A269 TP304 Tube OD Tolerance
	+		–
	inch	mm	inch	mm
1/8~1 1 /2	1/64(0.015)	0.4	1/32(0.031)	0.8
> 1 1 /2~4	1/32(0.031)	0.8	1/32(0.031)	0.8
> 4~8	1/16(0.062)	1.6	1/32(0.031)	0.8
> 8~18	3/32(0.093)	2.4	1/32(0.031)	0.8
> 18~26	1/8(0.125)	3.2	1/32(0.031)	0.8
> 26~34	5/32(0.156)	4	1/32(0.031)	0.8
> 34~48	3/16(0.187)	4.8	1/32(0.031)	0.8

 

Wall Thickness Tolerance ASTM A269 TP304 Tube

NPS	ASTM A269 TP304 Tube Tolerance, %
	+	–
1/8-2 1 /2	20	12.5
3~18, t/D≤ 5%	22.5	12.5
3~18, t/D> 5%	15	12.5
≥ 20, welded	17.5	12.5
≥ 20, seamless, t/D≤ 5%	22.5	12.5
≥ 20, seamless, t/D> 5%	15	12.5

 

Application

Chemical and petrochemical
Power generation
Renewable energy
Pulp and Paper
Process piping
Pharmaceutical
Food and beverage
Oil and gas
Mining
Water/waste

 

Non-Destructive Testing

Eddy Current Testing: Provides 100% coverage to detect minute defects within the tube wall.
Hydrostatic Testing: Maintains a standard pressure for a specified duration to ensure the absence of any leaks.
Additionally, we offer Air Under Water Testing, specifically designed for environments involving highly permeable gases.

 

Packaging and Marking:

The products shall be packaged in bundles or plywood crates, wrapped in plastic, and provided with appropriate protective measures to ensure seaworthy transport, or packaged in accordance with specific requirements.
Markings shall indicate whether the tubing is hot-worked or cold-worked, and shall include-but not be limited to-the following information: standard, grade, dimensions, heat number, and batch number.