UNS S31703|1.4438|TP317L Seamless Stainless Steel Pipe

Seamless Stainless Steel TP317L Pipes (UNS S31703 / W.Nr. 1.4438) are high-performance austenitic solutions specifically engineered for superior resistance to localized chemical attack and pitting. As a premier manufacturer based in Wenzhou, China, XinZhe produces high-integrity seamless piping that strictly complies with ASTM A312, ASTM A213, and ASME SA213 international standards.

Distinguished by its increased Molybdenum (3% min) and low-carbon content, our TP317L tubing offers significantly enhanced resistance to pitting and crevice corrosion compared to standard 316L grades, especially in acidic chloride environments. These pipes are indispensable for mission-critical applications in flue gas desulfurization (FGD), chemical reactors, and pulp and paper processing. Through advanced cold-drawing and precise solution annealing, XinZhe ensures every pipe maintains a uniform microstructure and excellent weldability for the most aggressive industrial media.

PREN ≈ 28-30 ,higher than TP316L PREN 24-25

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What Is Seamless Stainless Steel TP317L Pipe?

To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for 317L stainless steel.

The composition of Stainless Steel TP317L is carefully balanced to achieve its superior corrosion resistance and high strength.

Product Overview

Seamless Stainless Steel TP317L Pipe (UNS S31703 / EN 1.4438) is a high-alloy austenitic stainless steel pipe manufactured through a seamless process from a solid billet.

Compared with welded pipes, TP317L seamless pipes offer:

No weld seams (eliminating structural weak points)
Uniform wall thickness
Higher pressure resistance
Superior reliability in critical applications

These characteristics make TP317L an ideal choice for high-pressure, high-temperature, and corrosive environments.

High Molybdenum Content (≥ 3.0%)

Enhances resistance to:

Pitting corrosion
Crevice corrosion
Chloride attack

Significantly outperforms 316L stainless steel in aggressive environments.

Low Carbon Content (≤ 0.03%)

Prevents:

Sensitization during welding
Intergranular corrosion

This eliminates the need for post-weld heat treatment (PWHT).

1. Excellent Corrosion Resistance

High chromium and molybdenum content provides strong resistance against:

Sulfuric acid
Phosphoric acid
Chloride-rich media

2. Superior Mechanical Strength

Seamless construction ensures:

High pressure-bearing capacity
Enhanced structural integrity
Long service life

3. Outstanding Weldability

Low carbon composition ensures:

Stable microstructure in the Heat Affected Zone (HAZ)
Maintained corrosion resistance after welding

Standards & Dimensional Tolerances

Manufactured in compliance with:

ASTM A312
ASME SA312
JIS G3459
GB/T 14976

Product Specifications and Data

To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for 317L stainless steel.

Chemical Composition

The composition of Stainless Steel TP317L is carefully balanced to achieve its superior corrosion resistance and high strength.

Cr	Ni	P	S	Mo	Mn	Si	C
18.00 - 20.00	11.00 - 15.00	≤ 0.045	≤ 0.030	3.00 - 4.00	≤ 2.00	≤ 1.00	≤ 0.035

Typical Mechanical Properties of Stainless Steel TP317L

Stainless Steel TP317L is specifically designed to maintain its strength and shape in high-stress, corrosive environments.

Tensile Strength	Yield Strength	Elongation	Hardness
≥ 515 MPa	≥ 205 MPa	≥ 35%	≤ 192 HBW

Typical Physical Properties of Stainless Steel TP317L

These physical properties highlight the material's ability to perform reliably under a wide range of conditions.

Density	Melting Point	Thermal Expansion	Thermal Conductivity	Modulus of Elasticity	Electrical Resistivity
8.0 g/cm³	1398 - 1454 °C	16.6 µm/m·°C (20-100°C)	16.3 W/m·K (20°C)	193 GPa	0.74 x 10⁻⁶ Ω·m (20°C)

Size Tolerance Chart

Standard	OD(D)	Tolerance （MM)		Thickness(S)	Tolerance(MM)	Length	Tolerance
	MM	Common	High	MM			MM
ASTM A312	D ≤48.3	+0.4/-0.8		10.3 ≤73	+20%-12.5%		+6.0/0
	48.3 ≤114.30	±0.8		88.9 ≤457.2,t/D ≤5%	+22.5%/-12.5%
	114.3 ≤219.1	+1.6/-0.8		88.9 ≤457.2,t/D >5%	+15%/-12.5%
	219.1 ≤457.2	+2.4/-0.8		D ≥508, t/D≤5%,SMLS	+22.5%/-12.5%
	457.2 ≤660.4	+3.2/-0.8		D ≥508, t/D>5%,SMLS	+15%/-12.5%
	660.4 ≤863.6	+4.0/-0.8		D ≥508, WELD	+17.5%/-12.5%
	863.6 ≤1219.2	+4.8/-0.8
JIS 3459 Hot-Finished Smls Pipe	D ＜50	±0.51		S ＜4	±0.5
	D ≥50	±1.0%		S ≥4	±12.5%
JIS 3459 Cold-Finished	D ＜30	±0.3		S ＜2	±0.2
	D ≥30	±1.0%		S ≥2	±10.0%
JIS G3463 Hot-Finished Smls Pipe	100	+0.4/-0.8		D ＜100， S	/	D	+7/0
				D ＜100， 2≤S	+40%/0	D	+10/0
				D ＜100， 2.4≤S	+35%/0
				D ＜100， 3.8≤S	+33%/0
				D ＜100， 4.6≤S	+28%/0	D	+13/0
	100 ≤D	+0.4/-1.2		D>100, S ＜2	/
	120 ≤D			D>100 ， 2≤S	/	D	+15/0
	160 ≤D	+0.4/-1.8		D>100 ， 2.4≤S	+35%/0
	200 ≤D	+0.4/-2.4		D>100 ， 3.8≤S	+33%/0	D>50,7	+10/0
				D>100 ， 4.6≤S	+28%/0
JIS G3463 Cold-finished		+0.4/-0.8		D	+0.4/0
	60 ≤D	±0.3		D ≥2.0	+20%/0	D>50,7	+13/0
	80 ≤D	±0.4		D ≥40	+22%/0
	100 ≤D	+0.4/-0.6
	120 ≤D	+0.4/-0.8				D>50,10M	+15/0
	160 ≤D	+0.4/-1.2
	200 ≤D	+0.4/-1.6
GB/T 14975 冷拔(扎)钢管	D	±0.3	±0.1	所有壁厚，普通级PA	+12.5%/-10%
	12.7		±0.15
	38.1	±0.4	±0.3
	88.9	±0.9%	±0.4
	139.7		±0.8	所有壁厚，高级PC	±10%
	203.2		±1.1
	219.1		±1.6
	D ≥323.9		±0.5%
GB/T 14976 冷拔(轧)钢管	6	±0.2	±0.15	S ≤3	±12%(10% /0 高级PC)
	10 ≤D	±0.2	±0.2
	30 ≤D	±0.2	±0.3	S>3	+12.5%/-10%(10%/0 高级PC)
	50 ≤D	0.85%	0.75%
	D>219	0.9%	0.8%	Smin, all	+22%/0(+20%/0 高级PC)

Typical Applications

TP317L seamless stainless steel pipes are widely used in:

Pulp & Paper Industry Bleaching systems and sulfite processing
Chemical & Petrochemical Industry Acidic and chloride-containing systems
Pharmaceutical & Food Processing Hygienic pipelines requiring high corrosion resistance
Marine Engineering Seawater systems, desalination plants, offshore platforms

Quality Assurance & Testing

All TP317L pipes undergo strict quality control procedures:

Certification

EN 10204 3.1 / 3.2 Mill Test Certificate (MTC), Full traceability of raw materials

Non-Destructive Testing (NDT)

PMI (Positive Material Identification), Eddy Current Testing (ET), Ultrasonic Testing (UT)

Mechanical Testing

Flattening Test, Flaring Test, Bending Test, Grain Size Analysis

Corrosion Testing

Intergranular Corrosion (IGC) Test, Pitting Resistance Test

Frequently Asked Questions

Why Choose TP317L Stainless Steel Pipe?

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Send your Seamless Stainless Steel TP317L Pipe enquiry with grade, applicable ASTM/ASME standard and edition, OD × wall thickness, length, quantity, end finish, delivery destination and inspection documents — you will get a written quotation stating the specification and edition, delivery condition, documents included and lead time.

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