Code Symbol Stamps		Code books Required	Remarks
	PP : Pressure Piping	Ⅰ: Power Boilers Ⅱ: Materials (Part A, B, C, D) Ⅴ: Nondestructive Examination Ⅸ: Welding & Brazing Qualifications B31.1 : Power Piping	3 years 3 years
	S : Power Boilers
	U : Pressure Vessels (Div. 1)	Ⅱ: Materials (Part A, B, C, D) Ⅴ: Nondestructive Examination Ⅷ: Pressure Vessels, Division 1 Ⅸ: Welding & Brazing Qualifications	3 years 1 year
	UM : Miniature Pressure Vessels
	U2 : Pressure Vessels (Div. 2)	Ⅱ: Materials (Part A, B, C, D) Ⅴ: Nondestructive Examination Ⅷ: Pressure Vessels, Division 2 - Alternative Rules Ⅸ: Welding & Brazing Qualifications	3 years
	U3 : High Pressure Vessels (Div. 3)	Ⅱ: Materials (Part A, B, C, D) Ⅴ: Nondestructive Examination Ⅷ: Pressure Vessels, Division 3 Ⅸ: Welding & Brazing Qualifications	3 years
	NV : Nuclear Safety and Pressure Relief Valves	Ⅲ: Rules for Construction of Nuclear Power Plant Components. Subsection NCA Ⅱ: Materials (Part A, B, D) Ⅴ: Nondestructive Examination Ⅸ: Welding & Brazing Qualifications PTC 25.3 : Safety and Relief Valves NQA-1 : Quality Assurance Program Requirements for Nuclear Facilities	3 years
	N Type Certificates of Authorization and Certificates of Accreditation N, NA, NPT, NS	Ⅲ: Rules for Construction of Nuclear Power Plant Components. Subsection NCA Ⅱ: Materials (Part D) Ⅴ: Nondestructive Examination Ⅸ: Welding & Brazing Qualifications NQA-1 : Quality Assurance Program Requirements for Nuclear Facilities	3 years

Code Symbol Stamps		Code books Required	Remarks
	N Type Certificates of Authorization and Certificates of Accreditation N, NA, NPT, NS	Ⅲ: Rules for Construction of Nuclear Power Plant Components. - Div. 3 Ⅱ: Materials (Part D) Ⅴ: Nondestructive Examination Ⅸ: Welding & Brazing Qualifications NQA-1 : Quality Assurance Program Requirements for Nuclear Facilities	3 years