Stainless steel oil cracking pipes are specialized austenitic and ferritic alloys engineered for severe petrochemical environments, delivering exceptional corrosion resistant stainless pipes in fluid catalytic cracking (FCC) and thermal cracking processes. Grades such as 304, 316, 321, and 347 provide robust protection against high-temperature sulfidation, oxidation, and carburization up to 760°C, forming stable chromia layers that prevent scaling and metal loss in hydrocarbon-rich atmospheres. Compliant with ASTM A312 and A213, these high temperature petrochemical pipes are essential for seamless or welded transfer lines, furnace tubes, and heat exchangers in refineries, where petrochemical cracking tubes must endure aggressive sulfur compounds, cyanides, and naphthenic acids without pitting or stress corrosion cracking.

Fabricated via hot extrusion or cold drawing with solution annealing at 1010-1120°C, stainless steel oil cracking pipes achieve superior creep strength and ductility, with stabilized variants like 321 (titanium-added) and 347 (niobium-stabilized) mitigating sensitization during welding to avoid polythionic acid attack in shutdowns. Their austenitic structure offers twice the thermal conductivity of carbon steel, optimizing heat transfer in FCC unit pipes while resisting erosion from catalyst particulates in risers and regenerators. Available in schedules 10S to 80S, outer diameters from 10.3mm to 323.9mm, and lengths up to 12m, they feature polished surfaces free of scale and seams, supporting custom beveling and U-bends for efficient installation in cracking coils and overhead condensers.

In petrochemical cracking tubes applications, these pipes excel by countering fireside corrosion from coke burning and flue gases at 566-760°C, with 304 providing excellent naphthenic acid resistance between 260-399°C and 316 enhancing pitting protection via 2-3% molybdenum. Rigorous NDT including ultrasonic, eddy current, and hydrostatic testing to 1.5x design pressure ensures zero defects, yielding minimum tensile strengths of 515-655 MPa and elongations of 40% for reliable pressure handling up to 150 bar. Optional linings like refractory or ceramic coatings further bolster durability in erosive recycle streams, while plain or threaded ends facilitate seamless integration with valves and fittings.

Compared to carbon steel, corrosion resistant stainless pipes like 347H demonstrate 20-30% higher rupture strength at 650°C and better resistance to 885°F embrittlement, enabling thinner walls for cost savings in ethylene crackers and hydrocracking units. Duplex grades such as 2205 offer hybrid austenitic-ferritic benefits for chloride-laden overheads, combining high yield strength with superior stress corrosion cracking resistance. Their non-magnetic properties support electromagnetic flaw detection, and eco-friendly recyclability aligns with sustainable refining practices, making them ideal for high temperature petrochemical pipes in delayed coking drums and fractionator internals.

Tackling key challenges like cyanide-induced pitting in fractionator overheads or catalyst erosion in feed nozzles, FCC unit pipes extend operational life by 40-60%, minimizing unplanned shutdowns and maintenance in high-throughput refineries. For operators seeking durable stainless steel oil cracking pipes or versatile petrochemical cracking tubes for reformers, these solutions deliver proven integrity, safety, and efficiency in global oil processing infrastructures.

Common Corrosive Compounds in Oil and Gas Processes

The following are some of the most prevalent corrosive compounds encountered across various processes in the oil and gas industry:

Sulphur: Present in raw crude, sulphur combines with other elements to form sulphides, sulphuric acids, polythionic acids, and other aggressive compounds. It can also cause sulphidation of metals at high temperatures.
Naphthenic Acid: A group of organic acids typically found in Western and Mid-East US crude oils.
Polythionic Acid: Typically created during equipment downtime, these acids result from the interaction of sulphides, moisture, and oxygen.
Chlorides: Often found in catalysts, cooling waters, and crude oil, salts such as magnesium chloride and calcium chloride can significantly increase corrosion rates.
Carbon Dioxide: A byproduct of hydrogen plants and catalytic cracking processes, carbon dioxide forms carbonic acid when combined with moisture.
Ammonia: Often the precursor to other corrosive substances—such as ammonium chloride—ammonia commonly arises from the interaction of hydrogen with nitrogen in feedstocks.
Cyanides: Responsible for accelerating corrosion rates, cyanides often form during the cracking of nitrogen-rich feedstocks.
Hydrogen Chloride: Resulting from the hydrolysis of magnesium chloride and calcium chloride, hydrogen chloride appears in many vapor streams and converts to highly aggressive hydrochloric acid upon condensation.
Sulphuric Acid: Formed when sulphur trioxide, water, and oxygen combine, this aggressive compound also serves as a process catalyst in alkylation plants.
Hydrogen: While not directly corrosive, hydrogen contributes to steel embrittlement and readily interacts with other compounds to generate corrosive agents.
Phenols: Frequently encountered in processes involving sour water strippers.
Oxygen: Like hydrogen, oxygen poses no direct threat and is essential for refreshing stainless steel’s passivation layer. However, it participates in processes that can lead to oxidation or scaling.
Carbon: Not directly corrosive, but at higher temperatures, it can cause carburization, leading to steel embrittlement and diminished corrosion resistance that allows other compounds to initiate attacks.

Superior Advantages of Stainless Steel

This positions stainless steel as a superior material unmatched by few other metals. While carbon steel may suffice in low-temperature, low-pressure, or low-corrosion environments, the diverse range of stainless steel alloys ensures optimal protection against even the most aggressive conditions in oil and gas refining processes.

Superior Advantages of Stainless Steel

Surface Finishing and Quality Assurance

We perform triple polishing to achieve a perfectly bright and smooth surface, free from any quality deficiencies.

Our precision equipment enables comprehensive testing in accordance with required standards, complemented by Positive Material Identification (PMI) tests to verify material integrity prior to delivery.

Material Sourcing and Quality Control

Our stainless steel round bars are sourced from premium suppliers Jiuli and Baosteel in China, ensuring rigorous quality control from the outset.

Chemical Composition

Typical composition for common grades used in oil cracking (wt. % max unless specified; balance Fe).

Chemical Composition of Stainless Steel Oil Cracking Pipes
Grade	C	Mn	Si	P	S	Cr	Ni	Others
304	0.08	2.00	0.75	0.045	0.030	18.0-20.0	8.0-10.5	N: 0.10
316	0.08	2.00	0.75	0.045	0.030	16.0-18.0	10.0-14.0	Mo: 2.0-3.0
321	0.08	2.00	0.75	0.045	0.030	17.0-19.0	9.0-12.0	Ti: 5xC min
347	0.08	2.00	0.75	0.045	0.030	17.0-19.0	9.0-13.0	Nb+Ta: 10xC min
2205 (Duplex)	0.03	2.00	1.00	0.030	0.020	22.0-23.0	4.5-6.5	Mo: 3.0-3.5; N: 0.14-0.20

Mechanical Properties

Minimum values at room temperature for annealed condition.

Mechanical Properties of Stainless Steel Oil Cracking Pipes
Grade	Tensile Strength (MPa)	Yield Strength (MPa)	Elongation (%)	Hardness (HB max)
304	515	205	40	201
316	515	205	40	217
321	515	205	40	217
347	515	205	40	217
2205	620	450	25	293

Key Benefits

Superior Sulfidation Resistance

High chromium protects against sulfur-induced corrosion in FCC regenerators and cracking coils up to 760°C.

High-Temperature Creep Strength

Austenitic grades maintain integrity under prolonged heat and pressure in petrochemical cracking tubes.

Pitting and Erosion Protection

Molybdenum-enhanced alloys resist cyanide pitting and catalyst wear in overhead lines and risers.

Weldable and Stabilized

321 and 347 grades prevent sensitization for crack-free welds in high temperature petrochemical pipes.

Extended Service Life

Reduces downtime by 40-60% in FCC units, lowering costs for stainless steel oil cracking pipes.

Versatile Fabrication

Supports seamless/welded forms with custom tolerances for petrochemical cracking applications.

Key Grades and Performance Characteristics

We typically utilize grades 304, 316, 405, and 410. Grade 304 performs exceptionally well in temperatures ranging from 260–399°C (500–750°F), while 400-series stainless steels provide enhanced resistance at higher temperatures up to 343–371°C (650–700°F). Additionally, grade 304 offers superior resistance to naphthenic acid corrosion.

Comparison with Other Grades

Comparison of Oil Cracking Grades with Carbon Steel
Feature	304/316	321/347	Carbon Steel
Corrosion Resistance	Excellent (Sulfidation)	Superior (Stabilized)	Poor (Oxidation)
Max Temp (°C)	760	815	540
Creep Strength	High	Very High	Low
Cost	Medium	Medium-High	Low
Applications	FCC Risers	Furnace Tubes	Low-Temp Lines
Tensile Strength (MPa)	515 min	515 min	415 min
Key Advantage	Pitting Resistance	Anti-Sensitization	Economical

Dimension Chart

The following table provides key dimensions for ANSI stainless steel pipes according to ASTM A312/ASME SA312 standards. Wall thicknesses are listed for Schedules 5S, 10S, 40S, and 80S.

Nominal Pipe Size	OD (inches)	OD (mm)	Schedule 5S (inches)	Schedule 5S (mm)	Schedule 10S (inches)	Schedule 10S (mm)	Schedule 40S (inches)	Schedule 40S (mm)	Schedule 80S (inches)	Schedule 80S (mm)
1/8	0.405	10.3	0.035	0.89	0.049	1.24	0.068	1.73	0.095	2.41
1/4	0.54	13.7	0.049	1.24	0.065	1.65	0.088	2.24	0.119	3.02
3/8	0.675	17.1	0.049	1.24	0.065	1.65	0.091	2.31	0.126	3.2
1/2	0.84	21.3	0.065	1.65	0.083	2.11	0.109	2.77	0.147	3.73
3/4	1.05	26.7	0.065	1.65	0.083	2.11	0.113	2.87	0.154	3.91
1	1.315	33.4	0.065	1.65	0.109	2.77	0.133	3.38	0.179	4.55
1-1/4	1.66	42.2	0.065	1.65	0.109	2.77	0.14	3.56	0.191	4.85
1-1/2	1.9	48.3	0.065	1.65	0.109	2.77	0.145	3.68	0.2	5.08
2	2.375	60.3	0.065	1.65	0.109	2.77	0.154	3.91	0.218	5.54
2-1/2	2.875	73	0.083	2.11	0.12	3.05	0.203	5.16	0.276	7.01
3	3.5	88.9	0.083	2.11	0.12	3.05	0.216	5.49	0.3	7.62
4	4.5	114.3	0.083	2.11	0.12	3.05	0.237	6.02	0.281	7.14
5	5.563	141.3	0.109	2.77	0.134	3.4	0.258	6.55	0.375	9.52
6	6.625	168.3	0.109	2.77	0.134	3.4	0.28	7.11	0.432	10.97
8	8.625	219.1	0.109	2.77	0.148	3.76	0.277	7.04	0.322	8.18
10	10.75	273.1	0.134	3.4	0.165	4.19	0.307	7.8	0.365	9.27
12	12.75	323.8	0.156	3.96	0.18	4.57	0.33	8.38	0.375	9.52

FAQs

They offer high Cr content for oxidation and sulfidation resistance at 566-760°C, preventing scaling in regenerators and risers unlike carbon steel.

316 provides better pitting resistance via molybdenum for chloride/cyanide environments, while 304 excels in general high-temp oxidation at lower cost.

Yes, stabilized 321/347 grades weld via TIG without PWHT, resisting polythionic cracking in stainless steel oil cracking pipes.

From 10.3mm to 323.9mm OD, SCH 10S-80S walls, seamless/welded, customizable for FCC and cracking furnace needs.

Stainless steel pipes for oil cracking

Stainless steel pipes for oil cracking

Common Corrosive Compounds in Oil and Gas Processes

Superior Advantages of Stainless Steel

Superior Advantages of Stainless Steel

Surface Finishing and Quality Assurance