API 5L GRB-X70 NACE MR0175 Sour Services H2S HIC Test Seamless Steel Pipe
Product Introduction: API 5L Seamless Line Pipe (NACE MR0175 / ISO 15156)
We are pleased to offer high-quality API 5L Seamless Steel Pipes, specifically manufactured to meet the stringent requirements of NACE MR0175 / ISO 15156 for Sour Service.
Product Standard: API SPEC 5L (PSL1 & PSL2)
Sour Service Compliance: NACE MR0175 / ISO 15156 (Petroleum and natural gas industries-Materials for use in H2S-containing environments in oil and gas production).
Manufacturing Type: Seamless (SMLS)
Outer Diameter:21.3mm (1/2") to 914mm (36") and above (hot-expanded) -1-3.
Wall Thickness:SCH 10 through SCH 160, XXS, or specific wall thicknesses up to 60mm.
Length:Single Random Length (SRL), Double Random Length (DRL), or fixed lengths as per client specifications.
Why NACE MR0175?
NACE MR0175 is the international standard for materials resistant to Sulfide Stress Cracking (SSC) and Hydrogen Induced Cracking (HIC) . In environments containing Hydrogen Sulfide (H₂S) -commonly known as "sour service"-standard carbon steel pipes are prone to brittle failure. Our pipes are optimized with strict chemical composition control and hardness limits to ensure safety and longevity in sour oil and gas fields
Chemical Composition (Key Requirements for NACE)
To qualify for NACE MR0175, the steel must have a controlled "Hardness" and specific chemistry. The typical requirements for sour service (PSL2) are stricter than standard PSL1
Element | Standard PSL1 (Max) | NACE MR0175 (Sour Service) (Max) | Impact |
Carbon (C) | 0.28 percent | 0.21 percent | Reduced to prevent hard spots |
Manganese (Mn) | 1.40 percent | 1.00 percent | Controlled to prevent segregation |
Phosphorus (P) | 0.03 percent | 0.02 percent | Tightly controlled for cleanliness |
Sulfur (S) | 0.03 percent | 0.00 percent | Extremely low for HIC resistance |
Hardness (HRC) | No specific limit | < 22 HRC | Critical to prevent SSC |
Mechanical Properties (API 5L PSL2)
While the mechanical strength matches standard API 5L grades, the hardness is strictly monitored. Below are the mechanical requirements for common grades:
Grade | Yield Strength (MPa) | Tensile Strength (MPa) | Hardness Requirement (NACE) |
X42 / L290 | 290 - 495 | 415 - 655 | ≤ 22 HRC / 237 HBW |
X52 / L360 | 360 - 530 | 460 - 760 | ≤ 22 HRC / 237 HBW |
X60 / L415 | 415 - 565 | 520 - 760 | ≤ 22 HRC / 237 HBW |
X65 / L450 | 450 - 600 | 535 - 760 | ≤ 22 HRC / 237 HBW |
X70 / L485 | 485 - 635 | 570 - 760 | ≤ 22 HRC / 237 HBW |
*Note: The Yield/Tensile ratio for PSL2 sour service pipes is typically capped at 0.93 to ensure ductility
Key Testing & Quality Controls
To ensure compliance with NACE MR0175, we conduct rigorous non-destructive and destructive testing:
"Hydrostatic Testing: 100% verification.
"Hardness Test: HRC/HB across pipe body, weld (if applicable), and HAZ.
"HIC Test (Hydrogen Induced Cracking): Per NACE TM0284.
"SSC Test (Sulfide Stress Cracking): Per NACE TM0177 (Method A, B, C, or D) .
"Impact Test (CVN): Mandatory for PSL2 to ensure toughness at specified temperatures.
Applications
Oil & Gas Transmission: Suitable for onshore and offshore pipelines containing wet H2S.
Refinery Piping: For processing crude oil with high sulfur content.
Natural Gas Sweetening Plants: Where amine treatment creates corrosive environments
