Guideline: Piping Materials Compatibility Table
Introduction
Selecting the right piping materials is critical for the safety, efficiency, and longevity of systems used in industries like oil & gas, chemical processing, and mining. Each of these industries operates in harsh environments, where piping must resist high pressures, extreme temperatures, and corrosive substances. Choosing incompatible materials could fail, leading to costly downtime, environmental hazards, and safety risks. This guide delves into the Piping Materials Compatibility Table, the most widely used piping materials, and their compatibility with fittings, flanges, valves, and fasteners, ensuring seamless operation across various industrial fields.
1. Overview of Key Materials in Piping Systems
Each industrial application comes with unique challenges, demanding materials with specific properties to withstand these conditions. Below is a breakdown of key piping materials and their characteristics:
Carbon Steel (ASTM A106): Commonly used in oil & gas for moderate temperature and pressure applications. Carbon steel is strong, durable, and cost-effective, making it suitable for general piping systems. However, it is prone to corrosion without proper protection or coatings.
Carbon Steel Alloy (ASTM A335): Designed for high-temperature service, carbon steel alloys like P11, P22, and P5 contain chromium and molybdenum, enhancing their strength and corrosion resistance at elevated temperatures.
Low-Temperature Carbon Steel (ASTM A333): Suitable for cryogenic applications, this alloy can maintain ductility at extremely low temperatures, making it ideal for LNG systems, natural gas transportation, and refrigerated chemical storage.
Stainless Steel (ASTM A312): Stainless steel grades like 304, 316, and 347 offer excellent corrosion resistance, high strength, and good formability. They are commonly used in chemical processing, where resistance to various chemicals is crucial.
API 5L (X42-X70): API 5L grades like X42, X52, and X70 are widely used in the oil and gas industry, particularly for pipelines transporting oil, gas, and water under high pressure. These grades are known for their strength, toughness, and weldability.
Duplex & Super Duplex Stainless Steel (ASTM A790): Duplex (UNS S31803, S32205) and super duplex (UNS S32750, S32760) stainless steels are known for their superior corrosion resistance, particularly in chloride-rich environments like offshore platforms. These materials provide high strength and excellent resistance to pitting and stress corrosion cracking.
2. Compatibility with Fittings, Flanges, Valves, and Fasteners
Compatibility between pipes and other components like fittings, flanges, valves, and bolts is essential for ensuring a safe, leak-free, and durable connection. Below, we explore how different materials match up across these components.
2.1 Carbon Steel Piping Systems
Pipes: ASTM A106 (Gr A/B/C) is the standard for high-temperature carbon steel piping.
Fittings: Carbon steel pipe fittings typically conform to ASTM A234 Gr WPB for welded configurations.
Flanges: ASTM A105 is the go-to for forged carbon steel flanges.
Valves: ASTM A216 Gr WCB valves are compatible with carbon steel pipes, offering durability and high-pressure performance.
Fasteners: ASTM A193 Gr B7 and A194 Gr 2H bolts and nuts are typically used for securing the flanges and other connections in carbon steel systems.
2.2 Alloy Steel Piping Systems (High-Temperature Service)
Pipes: ASTM A335 (Gr P1, P11, P22) is a staple for high-temperature piping in refineries and power plants.
Fittings: Alloy steel fittings made to ASTM A234 WP series offer good weldability and match with P-series pipes.
Flanges: ASTM A182 Gr F11 or F22 are common for flange material, depending on the pipe grade.
Valves: For high-temperature alloys, ASTM A217 Gr WC6 or WC9 valves provide reliable performance.
Fasteners: ASTM A193 Gr B7 with A194 Gr 2H nuts is a typical combination for alloy steel applications.
2.3 Low-Temperature Alloy Steel
Pipes: ASTM A333 (Gr 6 and 3) for applications down to -45°C, often used in cryogenic environments.
Fittings: ASTM A420 Gr WPL6 and WPL3 are low-temperature fittings compatible with A333 pipes.
Flanges: ASTM A350 Gr LF2/LF3 flanges are used in conjunction with low-temp piping.
Valves: ASTM A352 Gr LCB or LC3 valves are designed for low-temperature service.
Fasteners: ASTM A320 Gr L7 bolts and A194 Gr 7 nuts ensure durable connections at low temperatures.
2.4 Stainless Steel Piping Systems
Pipes: Austenitic stainless steel, like ASTM A312 Gr TP304, and TP316, is ideal for corrosion-resistant systems.
Fittings: ASTM A403 fittings (WP304/WP316) are widely used with stainless steel piping for chemical and marine applications.
Flanges: ASTM A182 Gr F304/F316 flanges complement the pipe materials.
Valves: A182 Gr F304/F316 valves are highly resistant to corrosive media, making them suitable for chemical plants and offshore environments.
Fasteners: ASTM A193 Gr B8/B8M bolts with A194 Gr 8/8M nuts are appropriate for stainless steel assemblies, ensuring corrosion resistance.
2.5 API 5L Grades for Oil & Gas Pipelines
Pipes: API 5L X42, X52, X65, and X70 grades provide high strength, flexibility, and toughness for oil and gas pipelines, especially in onshore and offshore applications.
Fittings: High-yield fittings, such as ASTM A860 Gr WPHY (42-70), match the strength of API 5L pipes.
Flanges: ASTM A694 Gr F42 to F70 flanges are suitable for high-pressure pipelines.
Valves: API 6D valves and ASTM A216 Gr WCB/WC6 are standard in these high-pressure environments.
Fasteners: Bolts conforming to ASTM A193 Gr B7 and nuts conforming to ASTM A194 Gr 2H ensure secure, high-pressure connections.
2.6 Duplex and Super Duplex Stainless Steel Systems
Pipes: Duplex stainless steel (UNS S31803/S32205) and super duplex (UNS S32750/S32760) pipes are highly resistant to both general and localized corrosion in chloride environments, making them ideal for offshore oil production and desalination plants.
Fittings: ASTM A815 Gr WP31803 and WP32750 fittings offer matching corrosion resistance and mechanical strength.
Flanges: ASTM A182 Gr F51/F53 flanges are standard for duplex systems.
Valves: Duplex valves, such as ASTM A182 Gr F51/F55, provide superior pitting resistance.
Fasteners: High-strength ASTM A193 Gr B7/B8M bolts and ASTM A194 Gr 7/8M nuts are commonly used.
Piping Materials Compatibility Table
| Material | Pipes | Fittings | Flanges | Valves | Bolts & Nuts |
| Carbon Steel | A106 Gr.A A106 Gr.B A106 Gr.C |
A234 WPA A234 WPB A234 WPC |
A105 | A216 WCB | A193 Gr.B7 A194 Gr.2H |
| Carbon Steel Alloy High-Temp | A335 P1 A335 P11 A335 P12 A335 P22 A335 P5 A335 P9 A335 P91 A225 P92 |
A234 WP1 A234 WP11 A234 WP12 A234 WP22 A234 WP5 A234 WP9 A234 WP91 A234 WP92 |
A182 F1 A182 F11 A182 F12 A182 F22 A182 F5 A182 F9 A182 F91 A182 F92 |
A217 WC1 A217 WC11 A217 WC12 A217 WC22 A217 WC5 A217 WC9 A217 WC91 A217 WC92 |
A193 Gr.B7 A194 Gr.2H |
| Carbon Steel Low-Temp | A333 Gr.6 A333 Gr.3 A333 Gr.1 |
A420 WPL6 A420 WPL3 A420 WPL1 |
A350 LF6 A350 LF3 A350 LF1 |
A352 LC6 A352 LC3 A352 LC1 |
A320 Gr.L7 A194 Gr.7 |
| Austenitic Stainless Steel | A312 TP304 A312 TP316 A312 TP321 A312 TP347 |
A403 WP304 A403 WP316 A403 WP321 A403 WP347 |
A182 F304 A182 F316 A182 F321 A182 F347 |
A182 F304 A182 F316 A182 F321 A182 F347 |
A193 Gr.B8 A194 Gr.8 |
| API 5L Line Pipe | API 5L X42 API 5L X46 API 5L X52 API 5L X56 API 5L X60 API 5L X65 API 5L X70 |
A860 WPHY 42 A860 WPHY 46 A860 WPHY 52 A860 WPHY 56 A860 WPHY 60 A860 WPHY 65 A860 WPHY 70 |
A694 F42 A694 F46 A694 F52 A694 F56 A694 F60 A694 F65 A694 F70 |
API 6D A216 WCB |
A193 Gr.B7 A194 Gr.2H |
| Duplex Stainless Steel | A790 UNS S31803 A790 UNS S32205 |
A815 WP31803 A815 WP32205 |
A182 F51 A182 F60 |
A182 F51 A182 F60 |
A193 Gr.B7 A194 Gr.7 |
| Super Duplex Stainless Steel | A790 UNS S32750 A790 UNS S32760 |
A815 WPS32750 A815 WPS32760 |
A182 F53 A182 F55 |
A182 F53 A182 F55 |
A193 Gr.B8M A194 Gr.8M |
3. Key Considerations for Material Selection
Temperature: High-temperature applications demand materials that can maintain mechanical properties at elevated temperatures, like ASTM A335 for steel alloys or A790 duplex stainless steels.
Corrosive Environment: Offshore and chemical processing applications involve exposure to highly corrosive substances like chlorides, acids, and alkalis. Stainless steel, duplex, and super duplex alloys provide excellent resistance to these environments.
Pressure: High-pressure environments, such as pipelines in oil and gas, require materials like API 5L grades paired with high-yield fittings, valves, and fasteners.
Low-Temperature Resilience: Cryogenic or refrigerated systems, such as those handling LNG, necessitate materials like ASTM A333 that retain their toughness at low temperatures.
4. Conclusion
In the oil & gas, chemical processing, and mining industries, proper material selection for piping systems is a critical aspect of system reliability and safety. Understanding the compatibility between pipes, fittings, flanges, valves, and fasteners ensures the durability and performance of the entire system. By using materials like API 5L, ASTM A106, A335, A312, and duplex stainless steels, you can match the right components to your specific operational requirements, ensuring longevity and minimizing downtime due to corrosion or mechanical failure.
When selecting materials, always consult with material experts and engineers to evaluate the precise needs of your application, taking into consideration pressure, temperature, corrosive exposure, and mechanical stresses.
