ASTM A312 TP304/304L Seamless Stainless Steel Pipe

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Womic Steel supplies ASTM A312 TP304/304L seamless stainless steel pipe for high-temperature and general corrosive service applications across chemical processing, food and beverage, pharmaceutical, and industrial fluid transport. Grade 304 is the most versatile austenitic stainless steel, offering excellent corrosion resistance, formability, and weldability. The low-carbon version 304L provides enhanced resistance to intergranular corrosion after welding. Minimum yield strength of 205 MPa (30,000 psi) for TP304, 170 MPa (24,700 psi) for TP304L, and tensile strength of 515 MPa (74,700 psi) for TP304, 485 MPa (70,300 psi) for TP304L. The seamless manufacturing process includes hot rolling or cold drawing with full solution annealing, ensuring uniform grain structure and consistent mechanical properties without weld seams. Outside diameter from 21.3mm to 914mm (1/2″ – 36″), wall thickness from 0.5mm to 50mm (Schedule 5S to XXS), length up to 12m standard, custom lengths up to 18m. Mill certificate, hydrostatic test, 100% ultrasonic test, solution annealed and pickled finish, beveled or plain ends available. Suitable for chemical processing lines, heat exchangers, pressure vessels, pharmaceutical equipment, brewery and dairy piping, water treatment systems, and high-pressure fluid transport.

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Seamless Stainless Steel Pipe Size: Outside Diameter: 21.3mm – 914mm (1/2″ – 36″), Wall Thickness: 0.5mm – 50mm (Schedule 5S, 10S, 40S, 80S, 160, XXS), Length: 6m – 12m standard, custom lengths up to 18m

Standard & Grade of Seamless Stainless Steel Pipe: ASTM A312 TP304, TP304L; also ASME SA312; EN 10216-5 1.4301, 1.4307; Equivalent to AISI 304, 304L; JIS G3459 SUS304TP, SUS304LTP

Usage of Seamless Stainless Steel Pipe: Chemical processing lines, petrochemical plants, food and beverage processing, pharmaceutical manufacturing, dairy and brewery piping, heat exchangers and pressure vessels, high-pressure fluid transport, water treatment systems, pulp and paper industry, textile processing, cryogenic service (down to -250°C), architectural structural components, power generation auxiliary piping, oil and gas gathering lines

Womic Steel offering high quality & competitive prices of ASTM A312 TP304/304L seamless stainless steel pipe, SMLS stainless pipe, cold drawn seamless tube, seamless 304 pipe, high-temperature stainless seamless pipe. Mill certificate EN 10204 3.1/3.2, hydro test, UT, solution annealed, beveled/plain ends, pickled/polished finish available. Factory direct supply for industrial, chemical, and food processing projects worldwide.

Womic Steel: Manufacturing Capabilities & Company Strength

Womic Steel Group is a premier manufacturer and global exporter with over 20 years of expertise in producing stainless steel seamless tubular products. Our state-of-the-art seamless pipe production facility utilizes both hot-rolling and cold-drawing processes to achieve precise dimensions and superior surface quality:

Cold Drawn (CD) Seamless Line: For diameters from 21.3mm to 219.1mm (1/2″ – 8″), wall thickness from 1.0mm to 25mm. Cold drawing provides superior dimensional accuracy (tighter tolerances), excellent surface finish, and enhanced mechanical properties through work hardening followed by solution annealing. Preferred for precision applications in instrumentation, hydraulic lines, and pharmaceutical systems.

Hot Finished (HF) Seamless Line: For diameters from 114.3mm to 610mm (4″ – 24″), wall thickness from 4.0mm to 50mm. Hot rolling process produces heavy wall pipes for high-pressure service at cost-effective rates. Suitable for chemical process piping, heat exchanger shells, and pressure vessel applications.

Extrusion/Large Diameter Seamless Line: For diameters from 219mm to 914mm (8″ – 36″), wall thickness from 6.0mm to 50mm. Utilizes hot extrusion followed by pilger rolling to produce large diameter seamless pipes where welded pipes are not permitted or where corrosion allowance requires thick walls.

All seamless stainless steel pipes undergo solution annealing (heat treatment) at 1040-1120°C followed by water quenching or rapid cooling to dissolve carbides, relieve internal stresses from cold work, and restore full corrosion resistance, followed by pickling and passivation to remove heat scale.

Quality Certifications & Regulatory Compliance:

ISO 9001:2015 Certified

PED 2014/68/EU (CE Marking) for pressure equipment

EN 10204 3.2 Certification with third-party validation (TÜV, BV, SGS, LR)

Third-Party Inspection (TPI) approved by SGS, BV, ABS, DNV, TÜV

NORSOK M-650 (upon request for offshore applications)

ASME Boiler and Pressure Vessel Code (Section VIII, Div. 1) compliance

NACE MR0175 / ISO 15156 for sour service (upon request)

Production Flexibility:

Cold Drawn: 21.3–219.1mm OD × 1.0–25mm WT × ≤ 12m

Hot Finished: 114.3–610mm OD × 4.0–50mm WT × ≤ 12m

Extrusion/Large Diameter: 219–914mm OD × 6.0–50mm WT × ≤ 18m

Finishing options: Annealed and pickled, bright annealed (BA), polished (180# to 600#), mirror finish

Womic Steel supplies stainless steel seamless pipes to over 80 countries across chemical, petrochemical, pharmaceutical, food and beverage, and marine industries.

ASTM A312 TP304/304L: Material Composition & Performance Characteristics

ASTM A312 TP304 and TP304L are the most widely specified austenitic stainless steel grades for general corrosive service. Grade 304 contains 18% chromium and 8% nickel, providing excellent corrosion resistance in a wide range of environments. Grade 304L is the low carbon version (0.03% max carbon) offering improved resistance to intergranular corrosion after welding, eliminating the need for post-weld heat treatment in most applications.

Chemical Composition (Ladle Analysis, % by mass):

Element	TP304 (ASTM A312)	TP304L (ASTM A312)
C	≤ 0.08	≤ 0.030
Mn	≤ 2.00	≤ 2.00
P	≤ 0.045	≤ 0.045
S	≤ 0.030	≤ 0.030
Si	≤ 1.00	≤ 1.00
Cr	18.0 – 20.0	18.0 – 20.0
Ni	8.0 – 11.0	8.0 – 12.0
N	≤ 0.10	≤ 0.10

Mechanical Properties (Room Temperature, Solution Annealed):

Property	TP304	TP304L
Yield Strength (min, 0.2% offset)	205 MPa (30,000 psi)	170 MPa (24,700 psi)
Tensile Strength (min)	515 MPa (74,700 psi)	485 MPa (70,300 psi)
Elongation (min, 50mm gauge)	35%	35%
Hardness (max)	90 HRB (192 HBW)	90 HRB (192 HBW)

Physical Properties:

Density: 7.93 g/cm³

Modulus of Elasticity: 193 GPa (28 × 10⁶ psi)

Thermal Conductivity: 16.2 W/m·K at 100°C

Coefficient of Thermal Expansion: 17.2 × 10⁻⁶/°C (0-100°C)

Electrical Resistivity: 72 μΩ·cm at 20°C

Corrosion Resistance:

Excellent resistance to oxidizing acids (nitric acid up to 65%)

Good resistance to organic acids and mild chloride environments

Good resistance to intergranular corrosion (TP304L superior after welding)

Acceptable for most food and beverage applications

Good corrosion resistance in atmospheric conditions

Limited resistance to reducing acids (hydrochloric, sulfuric) at elevated concentrations

Low-Temperature Properties:

TP304 and TP304L maintain excellent toughness down to -196°C (-320°F)

Accepted by ASME B31.3 for service at temperatures as low as -250°C without impact testing

No ductile-to-brittle transition; remains austenitic at cryogenic temperatures

Dimensional Range & Standards Compliance

Item	Specification
Standard	ASTM A312 / ASME SA312 (also A269, A213, A999)
Manufacturing Processes	Cold Drawn (CD), Hot Finished (HF), Extrusion
Outside Diameter Range	21.3mm – 914mm (1/2″ – 36″)
Wall Thickness Range	0.5mm – 50mm (Schedule 5S, 10S, 40S, 80S, 160, XXS)
Length Range	Standard: 6m; Extended: 12m, 18m, up to 18m
End Finish	Plain End (PE), Beveled End (BE), Threaded (upon request)
Surface Finish	Annealed & Pickled, Bright Annealed (BA), Polished (180# to 600#), Mirror (800#)
Tolerances (per ASTM A999)	OD: ±0.5% or ±3.2mm; WT: ±12.5% (OD < 4″) / ±15% (OD ≥ 4″); Length: +50mm / -0mm
Straightness	≤ 0.2% of total length (cold drawn); ≤ 0.25% (hot finished)

Available Dimensions & Specifications – ASTM A312 TP304/304L Seamless Stainless Steel Pipe (Selected Typical Sizes)

NPS	OD (mm)	Schedule	WT (mm)	Weight (kg/m)	Process	Standard Length	Typical Application
1/2″	21.3	40S	2.77	1.27	CD	6m	Instrumentation
3/4″	26.7	40S	2.87	1.69	CD	6m	Chemical dosing
1″	33.4	40S	3.38	2.50	CD	6m	Process lines
1-1/2″	48.3	40S	3.68	4.05	CD	6m	Food processing
2″	60.3	40S	3.91	5.44	CD	6m / 12m	Brewery lines
2-1/2″	73.0	40S	5.16	8.63	CD	6m / 12m	Hydraulic lines
3″	88.9	40S	5.49	11.3	CD/HF	6m / 12m	Heat exchangers
4″	114.3	40S	6.02	16.1	CD/HF	6m / 12m	Chemical process
5″	141.3	40S	6.55	21.8	HF	6m / 12m	Pressure vessels
6″	168.3	40S	7.11	28.3	HF	6m / 12m	Water treatment
8″	219.1	40S	8.18	42.6	HF/Ext	12m	Main header
10″	273.0	40S	9.27	60.3	HF/Ext	12m	Process piping
12″	323.9	40S	9.53	74.0	Ext	12m	Large diameter
14″	355.6	40S	11.13	94.6	Ext	12m	Pulp & paper
16″	406.4	40S	12.70	123.4	Ext	12m	Chemical plant
18″	457.2	40S	14.27	156.0	Ext	12m	Petrochemical
20″	508.0	40S	15.09	183.5	Ext	12m	Large volume
24″	609.6	40S	17.48	255.5	Ext	12m	Main headers
30″	762.0	Custom	15.9 – 30.0	Varies	Ext	12m	Special service
36″	914.4	Custom	19.0 – 40.0	Varies	Ext	12m	Large diameter

Custom dimensions outside these ranges available upon request. Hot finished pipes up to 610mm OD; larger sizes via extrusion.

Common Seamless Stainless Steel Pipe Standards & Grades Manufactured by Womic Steel

Standard	Steel Grades	Typical Application	Manufacturing Process
ASTM A312	TP304, TP304L, TP316, TP316L, TP321, TP347, TP309, TP310	High-temperature, general corrosive service	CD/HF/Ext
ASTM A213	TP304, TP304L, TP304H, TP316, TP316L, TP316H, TP321, TP321H, TP347, TP347H	Boiler, superheater, heat exchanger tubes	CD
ASTM A269	TP304, TP304L, TP316, TP316L, TP321	General service tubing (instrumentation, hydraulic)	CD
ASTM A511	304, 304L, 316, 316L	Mechanical tubing (hollow bar)	CD/HF
EN 10216-5	1.4301 (304), 1.4307 (304L), 1.4401 (316), 1.4404 (316L)	Pressure purposes, seamless stainless	CD/HF
JIS G3459	SUS304TP, SUS304LTP, SUS316TP, SUS316LTP	High pressure piping	CD/HF

Usage: Chemical processing, food and beverage, pharmaceutical, heat exchangers, pressure vessels, high-pressure fluid transport, instrumentation, hydraulic systems, power generation, oil and gas gathering, water treatment.

Manufacturing Process – Seamless Stainless Steel Pipe (Cold Drawn / Hot Finished / Extrusion)

Womic Steel employs three primary seamless manufacturing processes, selected based on diameter, wall thickness, and application requirements.

Cold Drawn (CD) Process – Small to Medium Diameter (21.3–219.1mm OD, 1.0–25mm WT):

1. Raw Material (Billet) Inspection: Stainless steel billet is verified for chemical composition per ASTM A312. Each billet has a unique heat number for full traceability.

2. Billet Preparation: Billets are cut to length, center-drilled, and heated to 1150-1250°C.

3. Piercing / Rotary Forging: Heated billet is pierced by a mandrel to create a hollow shell (mother tube) using a Mannesmann piercing mill.

4. Hot Rolling (Pilgrim / Continuous Mill): Hollow shell is rolled over a mandrel bar to reduce diameter and wall thickness to intermediate size.

5. Pickling (Hot Rolled): Scale removal before cold drawing.

6. Cold Drawing (Multiple Passes): Pipe is drawn through a die with a floating plug to achieve precise final dimensions (OD and ID). Multiple passes with intermediate annealing may be required for heavy reduction ratios. Cold drawing improves dimensional accuracy (tighter tolerances) and surface finish.

7. Solution Annealing (Heat Treatment): Pipe is heated to 1040-1120°C and rapidly cooled (water quench or forced air) to dissolve carbides and restore corrosion resistance.

8. Straightening: Multi-roll straightener ensures straightness ≤ 0.2% of length.

9. Cutting to Length: Automatic saw cut with precision length control.

10. Pickling & Passivation: Removal of heat scale and restoration of passive oxide layer.

11. Non-Destructive Testing: Eddy current test (100%) per ASTM A312; hydrostatic test (mandatory for pressure service).

12. Final Inspection & Marking: Permanent marking per ASTM A312 (grade, size, heat number, manufacturer).

Hot Finished (HF) Process – Medium to Large Diameter (114.3–610mm OD, 4.0–50mm WT):

1. Billet Heating: Billet heated to 1200-1280°C.

2. Piercing / Cross-Roll Piercing: Similar to CD process but without subsequent cold drawing.

3. Continuous Rolling (Mandrel Mill): Hot rolled to final dimensions in one continuous process.

4. Sizing Mill: Final diameter adjustment.

5. Solution Annealing: 1040-1120°C, water quench.

6. Straightening & Cut to Length

7. Pickling & Passivation

8. NDT: 100% UT or hydrostatic test.

9. Final Inspection & Marking

Extrusion Process – Very Large Diameter (219–914mm OD, 6.0–50mm WT):

1. Billet Preparation & Heating: Billet heated to 1150-1250°C.

2. Piercing / Pre-Piercing

3. Extrusion: Hot billet is forced through a die using a hydraulic press (3000-6000 tons force) to produce seamless pipe in one step. Capable of producing larger diameters than rolling processes.

4. Solution Annealing: 1040-1120°C, water quench.

5. Pickling & Passivation

6. NDT & Hydrostatic Test

7. Final Inspection & Marking

Advantages of Seamless Stainless Steel Pipe:

No weld seam – eliminates weld-related corrosion risks

Uniform grain structure and consistent mechanical properties

Higher pressure ratings than welded pipe of same dimensions (no weld joint efficiency factor)

Suitable for corrosive and high-purity applications where weld seams could trap contaminants

Available in sizes and wall thicknesses beyond welded capacity

Superior surface finish in cold drawn condition

Quality Control & Testing Procedures for ASTM A312 TP304/304L Seamless Stainless Steel Pipe

Stage	Inspection Method	Purpose
Raw Material (Billet)	Chemical Analysis (OES Spectrometer)	Verify TP304/304L composition limits (Cr 18-20%, Ni 8-11% for 304; C ≤ 0.03% for 304L)
Raw Material (Billet)	Tensile Testing	Verify mechanical properties per grade
In-Process	Dimensional Inspection (OD, WT)	Monitor dimensions during cold drawing / hot rolling
After Heat Treatment	Hardness Test (HRB/HV/HBW)	Verify proper solution annealing (≤ 90 HRB or ≤ 192 HBW)
Finished Pipe	Hydrostatic Test (Mandatory per ASTM A312 for pressure service)	Pressure integrity – 85-100% SMYS
Finished Pipe	Eddy Current Test (100%) – per ASTM A312	Detect surface and near-surface defects (substitutes for hydrotest for certain applications)
Finished Pipe	Flattening Test	Verify ductility (no cracks after flattening to 1/3 original OD)
Finished Pipe	Flaring Test	Verify ductility for tube expansion
Finished Pipe	Positive Material Identification (PMI)	Confirm grade (304 vs 304L)
Finished Pipe	Visual & Surface Inspection	Check for surface defects, pits, scratches, heat tint
Finished Pipe	Marking Verification	Ensure permanent marking per ASTM A312
Finished Pipe	Intergranular Corrosion Test (Practice E – ASTM A262)	Detect sensitization (if specified, optional for 304L)

Optional Tests for Critical Applications:

Low-temperature Impact Testing (Charpy V-Notch) – for cryogenic service (e.g., -196°C)

Pitting Corrosion Test (ASTM G48) – for chloride service qualification

Microstructure Examination (ASTM E112) – grain size measurement

Dimensional Tolerance Verification per ASTM A999

Full-length Ultrasonic Testing (not just eddy current) – for high-integrity applications

Primary Applications – ASTM A312 TP304/304L Seamless Stainless Steel Pipe

304/304L stainless steel seamless pipes are the most versatile corrosion-resistant piping solution across multiple industries:

Chemical Processing Industry: Transport of organic acids, alkalis, solvents, and intermediate chemicals. 304L preferred for welded systems to avoid intergranular corrosion. Seamless pipes eliminate weld seam corrosion concerns.

Petrochemical & Refinery: Cooling water lines, amine service, low pressure process piping, and secondary systems where corrosion resistance is required. Seamless construction preferred for high-pressure and high-temperature loops.

Food and Beverage Industry: Food grade stainless steel seamless pipe for dairy processing, brewery lines, juice production, edible oil transfer, and CIP (Clean-In-Place) systems. No weld seams means no bacteria-trapping crevices.

Pharmaceutical Industry: Purified water (PW) and Water for Injection (WFI) distribution piping. Seamless construction with electropolished interior finish (Ra ≤ 0.4μm) provides the highest level of cleanability.

Heat Exchangers & Pressure Vessels: Shell and tube heat exchangers, U-tube bundles, cooling coils, and pressure vessel shells. Seamless tubes per ASTM A213 are standard for heat exchanger service.

High-Pressure Fluid Transport: Hydraulic lines, instrument air lines, chemical injection lines, and high-pressure water jetting systems. Seamless pipe's uniform wall thickness provides reliability under cyclic pressure.

Water Treatment Systems: Reverse osmosis (RO) permeate piping, demineralized water distribution, and chemical feed lines where surface smoothness is critical to prevent scaling.

Cryogenic Service: Liquid nitrogen, LNG, and other cryogenic fluid handling (down to -196°C). 304/304L retains excellent toughness at cryogenic temperatures with no ductile-to-brittle transition.

Pharmaceutical & Biotech: Fermenter piping, clean steam systems, and high-purity water loops. Electropolished seamless tubing is standard for USP Class VI compliance.

Packaging & Shipping – ASTM A312 TP304/304L Seamless Stainless Steel Pipe

Packaging for Seamless Stainless Steel Pipes:

Anti-corrosion protection: Pipes are oiled or coated with VCI (Vapor Corrosion Inhibitor) paper. For food/pharmaceutical grades, no oil is used; pipes are wrapped in plastic film with end caps.

End caps: Heavy-duty plastic end caps (color-coded – typically red or transparent) protect beveled ends and prevent debris ingress. For polished pipes, soft plastic caps prevent scratching.

Bundling (Small diameters – ≤ 60mm): Pipes are bundled in hexagonal bundles (typically 50-100 pipes per bundle) with steel straps and protective corner guards. Interleaving paper between layers prevents surface scratching.

Individual packaging (Medium/Large diameters – > 60mm): Pipes are individually wrapped with plastic film with end caps.

Surface protection for polished finishes: For polished finishes (#180 to #600), adhesive PVC film is applied to protect the surface during transit. For mirror finish (800#), additional foam wrap is applied.

Wooden crates: For polished, sanitary, or pharmaceutical grade pipes, custom wooden crates with foam inserts are used.

Shipping:

Mode of transportation: Container vessels (20ft or 40ft containers), break-bulk vessels (for large diameters), or air freight (for urgent samples/emergency replacements).

Containerization: For diameters up to 610mm, pipes are loaded into standard 20ft or 40ft containers. For sanitary grade pipes, containers are lined with plywood to prevent damage.

Break-bulk loading: For large diameter pipes (> 610mm), direct loading into bulk carriers with dedicated pipe stowage plans.

Flat rack containers: For pipes exceeding standard container dimensions (length > 12m or diameter > 2.3m).

Labeling: Each bundle or individual pipe is labeled with material grade, standard, dimensions, heat number, and handling instructions.

Special handling for sanitary/pharmaceutical grade pipes: Sanitary tubing is shipped in dedicated containers with temperature-controlled packaging to prevent condensation and oxidation. End caps are sterile-grade and installed in cleanroom environment.

Documentation included with every shipment:

Mill Test Certificate (EN 10204 Type 3.1 or 3.2 upon request)

Hydrostatic Test Report (with pressure, duration, and expansion data)

Eddy Current/Ultrasonic Test Report (100% coverage)

Dimensional Inspection Report (OD, WT, length, straightness, ovality)

PMI Report (Positive Material Identification with grade verification)

Flattening & Flaring Test Reports

Packing List (with bundle/pipe numbers and weights)

Commercial Invoice and Packing List

Certificate of Origin (usually China, but can issue COO form E, form F, etc.)

For pressure equipment: CE Declaration of Conformity (if applicable)

For pharmaceutical grade: Cleanliness certificate, surface roughness (Ra) report

Womic Steel Advantages & FAQ – ASTM A312 TP304/304L Seamless Stainless Steel Pipe