ASTM A333 Grade 6 Pipe Carbon Steel Low-Temperature Seamless — Factory Direct Supplier | Huaxia-Steel

ASTM A333 Grade 6 seamless pipe is the standard low-temperature carbon steel pipe for cryogenic piping, LNG processing, ammonia plants, and cold-climate process systems. With mandatory Charpy impact testing at -46 degrees C (-50 degrees F), A333 Gr.6 carries the toughness needed for safe operation in cold-service duty. Huaxia-Steel supplies A333 Gr.6 seamless pipe in the full ASME B36.10 size range from Chinese mills with EN 10204 3.1 certificates and third-party inspection on request.

Product Overview

A333 Grade 6 seamless pipe is made by hot-piercing solid billet into a tube shell, then hot rolling or cold drawing to the final dimensions. The seamless construction removes the longitudinal weld and gives the pipe uniform mechanical properties in all directions – ideal for low-temperature and high-pressure service where a weld seam would be a weak point. The standard covers NPS 1/8 to NPS 48, in both standard and extra-strong wall thicknesses.

Specifications

Item	Details
Standard	ASTM A333/A333M
Grade	Grade 6 (low-temperature carbon steel)
Type	Seamless (SMLS)
Size range	NPS 1/8 to NPS 48 (DN 6 to DN 1200)
Wall thickness	SCH 10S to SCH 160, plus XXS, per ASME B36.10
Length	Single random 4-7 m, double random 7-14 m, or cut-to-length
Delivery condition	Normalized at 870-925 degrees C (mandatory per the standard)
Test temperature for Charpy	-46 degrees C (-50 degrees F) – mandatory

Available Grades

The A333 family includes multiple low-temperature grades; we supply them all on request:

ASTM A333 Grade 1 – service to -45 degrees C, fine-grain steel.
ASTM A333 Grade 3 – service to -100 degrees C, 3.5% nickel alloyed.
ASTM A333 Grade 4 – service to -100 degrees C, carbon-manganese fine-grain.
ASTM A333 Grade 6 – service to -45 degrees C, the standard low-temp carbon steel.
ASTM A333 Grade 7 – service to -60 degrees C, 2.5% nickel alloyed.
ASTM A333 Grade 8 – service to -100 degrees C, 8.5% nickel (cryogenic).
ASTM A333 Grade 9 – service to -50 degrees C, 2% nickel – 1% copper.
ASTM A333 Grade 10 – service to -60 degrees C, lean nickel.
ASTM A333 Grade 11 – service to -45 degrees C, fine-grain carbon-manganese.

Manufacturing Standards

ASTM A333/A333M – Standard specification for seamless and welded carbon and alloy steel pipe for low-temperature service.
ASTM A530/A530M – General requirements for specialized carbon and alloy steel pipe.
ASME B36.10 – Welded and seamless wrought steel pipe dimensional standard.
ASME B31.3 – Process piping code.
ASME B31.1 – Power piping code.
EN 10216-4 – Seamless steel tubes for pressure purposes, low-temperature service.

Applications

LNG processing and regasification plant piping
Ammonia and urea plant process piping
Ethylene and propylene refrigeration systems
Cryogenic storage tank piping and interconnecting lines
Refrigeration and chilled water systems in cold climates
Arctic and sub-arctic process plants, including oil and gas gathering
Low-temperature heat exchangers and vaporizers
Carbon dioxide (CO2) transport and sequestration lines

Mechanical Properties

Property	ASTM A333 Grade 6 requirement
Tensile strength minimum	415 MPa (60 ksi)
Yield strength minimum	240 MPa (35 ksi)
Elongation in 50 mm minimum	30% (for longitudinal specimens)
Charpy impact at -46 degrees C minimum	18 J average (3 specimens) – 14 J any one specimen
Hardness (typical, not a code requirement)	130-160 HB

The mandatory Charpy test at -46 degrees C distinguishes A333 Gr.6 from standard A106 Gr.B seamless pipe. Without the low-temperature impact test, A106 cannot be used in cold-service duty.

Heat Treatment and Welding

A333 Gr.6 is supplied in the normalized condition to refine the grain and ensure the impact toughness is met. Cold drawing is allowed after normalization as long as a final stress-relief or sub-critical anneal is performed.

Welding: Standard arc welding (SMAW, GMAW, FCAW, SAW) is suitable. Use low-hydrogen consumables and follow ASME B31.3 procedure qualifications.
Preheat: Generally not required for thin walls, but 50-100 degrees C is recommended for heavy walls or high-restraint joints to avoid hydrogen cracking.
PWHT: A stress-relief cycle at 595-650 degrees C is recommended for heavy-wall or sour-service piping.

Quality Assurance

Each A333 Grade 6 seamless pipe from Huaxia-Steel is shipped with:

Mill test certificate per EN 10204 3.1 with heat number, chemistry, tensile, and Charpy values.
Charpy impact test at -46 degrees C, three specimens per heat per lot.
Hydrostatic test at the required pressure (commonly 1.5 times the design pressure).
Dimensional inspection per ASME B36.10.
Visual and surface inspection per ASTM A530.
Supplementary tests on request: drop-weight tear test, hardness survey, flaring and flattening tests.

Independent third-party inspection by SGS, BV, TUV, or Lloyds can be arranged for code-stamped or government-tender projects.

Packing and Shipping

A333 Grade 6 pipe is bundled in hexagonal packs with steel strapping, end caps fitted, and VCI paper inside. Marking per ASTM A530 includes grade, size, schedule, heat number, and the standard reference. FOB, CFR, and CIF shipping from Tianjin and Shanghai are standard. DDP delivery to project sites is available on request.

Why Buy ASTM A333 Grade 6 from Huaxia-Steel?

Mill-direct pricing on normalized seamless low-temperature pipe
Full NPS 1/8 to NPS 48 size range with SCH 10S to XXS schedules
Charpy tested at -46 degrees C with full data on the mill certificate
Compatible fittings supply: ASME B16.9 A420 WPL6 low-temperature butt-weld fittings
Coordinated third-party inspection for code-stamped projects
Fast lead time for the most common sizes (4-6 weeks for custom orders)

Need ASTM A333 Grade 6 seamless pipe for a low-temperature project? Send the size, schedule, length, quantity, and supplementary test requirements. Our team will deliver a complete offer with normalized condition confirmation, Charpy data, and FOB/CIF pricing within two working days.