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Low Temperature Carbon Steel Seamless Pipes Supplier

ASTM A333 / ASME SA333 LTCS pipes, Grade 6, 1 & 3, impact tested for sub-zero service

LTCS Seamless Pipes to ASTM A333 for Sub-Zero Service

ASTM A333 low temperature carbon steel seamless pipes

Dinesh Tube India supplies low temperature carbon steel (LTCS) seamless pipes to ASTM A333 / ASME SA333 for piping that runs below 0 °C. That includes LPG and LNG plants, refrigeration systems, cold-climate pipelines and process lines that get chilled by depressurisation.

Ordinary carbon steel pipe can turn brittle and crack in the cold. LTCS pipe has controlled chemistry and heat treatment, and every heat is Charpy impact tested: at −45 °C for Grades 1 and 6, and down to −100 °C for 3.5% nickel Grade 3.

We supply LTCS seamless pipes from NPS 1/2" to 24" in all standard schedules, with an EN 10204 3.1 mill test certificate that reports impact test results. Most enquiries are for ASTM A333 Grade 6 pipe, the most widely used LTCS grade. For Grade 6 sizes, weights and pressure details, see that page. This page compares all the LTCS grades so you can choose the right one.

Table of Contents


What Is LTCS Pipe?

LTCS (low temperature carbon steel) pipe is carbon steel pipe that is proven by impact testing to stay tough at low temperatures. The governing standard is ASTM A333/A333M (ASME SA333). It covers seamless and welded carbon and alloy steel pipe for low temperature service, in nominal wall thickness. The general requirements come from ASTM A999.

A333 has several grades. Grades 1 and 6 are plain carbon-manganese steels, and these are what most buyers mean by "LTCS pipe". Grades 3, 7, 8 and 9 are nickel steels for colder service, down to −195 °C for 9% nickel Grade 8. Grade 6 is the most common choice because it matches the 415 MPa strength of ASTM A106 Grade B while adding guaranteed toughness at −45 °C.

Related grade page: ASTM A333 Grade 6 Carbon Steel Pipes: sizes, weights and pressure details

LTCS Seamless Pipe Specification

Standard

ASTM A333/A333M, ASME SA333/SA333M

Grades

Grade 6, Grade 1, Grade 3; other A333 grades on request

Pipe Size

NPS 1/2" – 24" (DN 15 – DN 600)

Schedule

SCH 10, 20, 30, 40, STD, 60, 80, XS, 100, 120, 140, 160, XXS

Type

Seamless (welded A333 on request)

Dimensions

ASME B36.10M

Length

Single random, double random, cut length up to 12 m

Ends

Plain end, bevelled end

Certification

EN 10204 3.1 MTC with impact results; third-party inspection on request

Optional Requirements

NACE MR0175 / MR0103 compliance, ultrasonic testing, PMI
LTCS seamless pipe specification

LTCS Impact Test Temperatures by Grade

The impact test temperature is the most important number when choosing an A333 grade. Pick a grade whose test temperature is at or below your minimum design metal temperature.

A333 GradeType of SteelImpact Test Temperature
Grade 6Carbon-manganese (LTCS)−45 °C (−50 °F)
Grade 1Carbon-manganese (LTCS)−45 °C (−50 °F)
Grade 10Carbon-manganese, micro-alloyed−60 °C (−75 °F)
Grade 72.5% nickel−75 °C (−100 °F)
Grade 92% nickel, copper−75 °C (−100 °F)
Grade 33.5% nickel−100 °C (−150 °F)
Grade 4Cr-Ni-Cu-Al low alloy−100 °C (−150 °F)
Grade 89% nickel−195 °C (−320 °F)

Charpy V-notch requirement for Grades 1, 3, 4, 6, 7, 9 and 10: 18 J (13 ft·lbf) minimum average of three full-size specimens, 14 J (10 ft·lbf) minimum single value. Grade 8 is accepted on lateral expansion.

LTCS Pipe Chemical Composition (%)

GradeC maxMnSiP maxS maxNiOther
Grade 60.300.29 – 1.060.10 min0.0250.025——
Grade 10.300.40 – 1.06—0.0250.025——
Grade 30.190.31 – 0.640.18 – 0.370.0250.0253.18 – 3.82—
Grade 40.120.50 – 1.050.08 – 0.370.0250.0250.47 – 0.98Cr 0.44–1.01, Cu 0.40–0.75, Al 0.04–0.30
Grade 70.190.90 max0.13 – 0.320.0250.0252.03 – 2.57—
Grade 80.130.90 max0.13 – 0.320.0250.0258.40 – 9.60—
Grade 90.200.40 – 1.06—0.0250.0251.60 – 2.24Cu 0.75–1.25
Grade 100.201.15 – 1.500.10 – 0.350.0350.0150.25 maxCr 0.15, Mo 0.05, Cu 0.15, V 0.12, Nb 0.05, Al 0.06 (all max)

LTCS Pipe Mechanical Properties

GradeTensile Strength (min)Yield Strength (min)Elongation, longitudinal (min)
Grade 6415 MPa (60 ksi)240 MPa (35 ksi)30%
Grade 1380 MPa (55 ksi)205 MPa (30 ksi)35%
Grade 3450 MPa (65 ksi)240 MPa (35 ksi)30%
Grade 4415 MPa (60 ksi)240 MPa (35 ksi)30%
Grade 7450 MPa (65 ksi)240 MPa (35 ksi)30%
Grade 8690 MPa (100 ksi)515 MPa (75 ksi)22%
Grade 9435 MPa (63 ksi)315 MPa (46 ksi)28%
Grade 10550 MPa (80 ksi)450 MPa (65 ksi)22%

Heat Treatment & Testing

A333 pipe must be heat treated to control its grain structure, because toughness depends on it. Grades 1 and 6 are normalized at 815 °C (1500 °F) or higher, or normalized and tempered. Seamless pipe can instead be made with controlled hot working and finishing temperature. Nickel grades are normalized, normalized and tempered, or quenched and tempered, depending on grade. Every lot is then tested:

  •   Charpy V-notch impact test: at the grade's test temperature
  •   Tension test: tensile, yield and elongation
  •   Hydrostatic or non-destructive electric test: every pipe, per A999
  •   Chemical analysis: heat and product analysis
  •   Dimensional and visual inspection: to ASME B36.10M and A999

LTCS (A333 Gr 6) vs Carbon Steel (A106 Gr B)

PropertyA333 Grade 6 (LTCS)A106 Grade B
ServiceLow temperatureAmbient and high temperature
Impact testedYes, at −45 °CNo
Typical lower limit (ASME B31.3, no extra testing)−45 °CAbout −29 °C
Carbon (max)0.30%0.30%
Tensile / yield (min)415 / 240 MPa415 / 240 MPa
Heat treatmentNormalized (or controlled hot working)Not required for hot-finished pipe

Because the strength values match, A333 Grade 6 is often dual-certified with A106 Grade B and used in place of it. Always check your project's minimum design metal temperature.

Need LTCS pipes for a low temperature line? Send the grade, NPS, schedule, length, quantity and design temperature to kamlesh@dineshtube-india.com or call +91 83559 10913. You can also send an enquiry.

LTCS Pipe Grades We Supply

ASTM A333 Grade 6 LTCS seamless pipe

A333 Grade 6 Pipe

The most common LTCS grade: 415 MPa tensile strength, impact tested at −45 °C.
ASTM A333 Grade 1 low temperature carbon steel pipe

A333 Grade 1 Pipe

Lower-strength LTCS grade with 380 MPa tensile strength, impact tested at −45 °C.
ASTM A333 Grade 3 3.5% nickel low temperature pipe

A333 Grade 3 Pipe

3.5% nickel steel for colder service, impact tested at −100 °C.

LTCS Fittings, Flanges & Tubes

A low temperature piping system needs every component impact tested to the same temperature. LTCS pipe is normally combined with:

ComponentLTCS Standard & Grade
Seamless pipeASTM A333 Grade 6
Butt-weld fittingsASTM A420 WPL6
Flanges and forged fittingsASTM A350 LF2
Small-diameter tubesASTM A334 Grade 1 / Grade 6

LTCS Pipe Applications

  •   LPG, LNG and propane storage and transfer lines
  •   Refrigeration and ammonia plants
  •   Gas processing, NGL recovery and cryogenic pre-cooling
  •   Flare and blowdown lines that chill on depressurisation
  •   Offshore and onshore oil and gas piping in cold climates
  •   Petrochemical and fertilizer plants
  •   Heat exchangers and pressure vessels in low temperature service

See also our carbon steel seamless pipes and API 5L line pipe.

LTCS Seamless Pipes: FAQs

What is LTCS pipe?

LTCS stands for low temperature carbon steel. LTCS pipe is carbon steel pipe made and impact tested to stay tough at sub-zero temperatures, most often to ASTM A333 / ASME SA333 Grade 6 or Grade 1. Each heat is Charpy impact tested at −45 °C (−50 °F), so the pipe can be used where ordinary carbon steel pipe could become brittle and crack.

What is the minimum temperature for LTCS pipe?

ASTM A333 Grade 1 and Grade 6 LTCS pipes are impact tested at −45 °C (−50 °F) and are generally used down to that temperature. For colder service, nickel-alloy grades are used: Grade 3 (3.5% Ni) is tested at −100 °C (−150 °F) and Grade 8 (9% Ni) at −195 °C (−320 °F). The design code for your project sets the final limit.

What is the difference between LTCS and carbon steel pipe?

Standard carbon steel pipe such as ASTM A106 Grade B is not impact tested, and under ASME B31.3 it is commonly limited to about −29 °C (−20 °F) without extra testing. LTCS pipe to ASTM A333 has controlled chemistry and heat treatment and is Charpy impact tested at −45 °C, so it can be used in colder service. A333 Grade 6 also has the same minimum tensile strength as A106 Grade B: 415 MPa (60 ksi).

What is the difference between A333 Grade 1 and Grade 6?

Both are low temperature carbon steel grades impact tested at −45 °C. Grade 6 has higher strength (415 MPa tensile, 240 MPa yield) than Grade 1 (380 MPa tensile, 205 MPa yield) and requires a minimum silicon content, so Grade 6 is the more widely specified LTCS grade for process and oil and gas piping.

Is A333 pipe seamless or welded?

ASTM A333 covers both seamless and welded pipe, with welding done without filler metal. Seamless A333 Grade 6 is the usual choice for high-pressure and critical low temperature lines. We supply seamless LTCS pipe as standard; welded A333 pipe can be quoted on request.

What fittings and flanges are used with LTCS pipe?

LTCS piping systems usually combine ASTM A333 Grade 6 pipe with ASTM A420 WPL6 butt-weld fittings and ASTM A350 LF2 forged flanges and fittings, all impact tested at −45 °C. For small-diameter tubing in the same service, ASTM A334 Grade 1 or Grade 6 tubes are used.

Export Destinations for LTCS Pipes

We export low temperature carbon steel seamless pipes to the Middle East (UAE, Saudi Arabia, Qatar, Kuwait, Oman, Bahrain, Iraq), Africa (Nigeria, Egypt, Algeria, South Africa, Angola), Asia (Singapore, Malaysia, Indonesia, Thailand, Vietnam, South Korea, Japan, Kazakhstan), Europe (Norway, United Kingdom, Netherlands, Italy, Poland, Romania, Turkey), and the Americas (United States, Canada, Brazil, Chile, Argentina).