The maximum allowable design stress limits for 9% nickel steel plates generally depend on specific design Codes:

• ASME BPVC Section VIII, Division 1: according to Table UHT-23, the maximum allowable design stress for 9% nickel steel(base metal) in both NNT & QT conditions is 25 ksi. The maximum limit for 9% nickel steel (welded) in both NTT & QT conditions is 23.7 ksi.
• ASME BPVC Code Case 1499: the maximum allowable design stress for both NNT & QT 9% nickel steel is 25 ksi; welded products must meet minimum tensile strength of 100 ksi.
• ASME BPVC Section VIII, Division 2: according to Table AQT-1, the maximum allowable design stress for 9% nickel steel(base metal) in both NNT & QT conditions is 33.3 ksi. The maximum limit for 9% nickel steel (welded) in both NTT & QT conditions is 31.7 ksi.
• API Standard 620: for large low-pressure welded storage tanks for liquefied natural gas, according to Table Q.3.3, the maximum allowable design stress for 9% nickel steel (welded) in both NNT & QT conditions is 31.7 ksi; the tensile strength shall be no less than 95 ksi in welded construction.