1. Q: What does the "X" designate in API 5L grades like X70?
A: The "X" denotes a minimum yield strength in ksi (thousands of psi). X70 has a minimum yield strength of 70,000 psi (483 MPa).
2. Q: Which standard covers welded stainless-steel pipe but is sometimes referenced alongside carbon steel for corrosion applications?
A: ASTM A312 covers seamless and welded austenitic stainless steel pipe. For corrosive environments where carbon steel is insufficient, carbon steel may be clad or replaced with A312 grades like 304/304L or 316/316L.
3. Q: What is a key characteristic of ASTM A252 pipe?
A: ASTM A252 covers welded or seamless steel pipe used as piles. It's valued for structural strength rather than pressure integrity.
4. Q: Is ASTM A135 pipe suitable for pressure applications?
A: Yes, ASTM A135 is an ERW pipe specification specifically for pressure applications, available in Grades A and B with yield strengths similar to A53.
5. Q: What is the primary purpose of ASTM A587 pipe?
A: ASTM A587 covers electric-welded low-alloy steel pipe used for chemical industry service, often chosen for its corrosion resistance in specific environments.
