ES&H Manual

Pressure and Vacuum Systems Safety Supplement

Part 3: Equivalent Measures



Part 3:               Equivalent Measures


Equivalent measures shall be used to ensure a level of safety equal to or greater than that required by ASME Pressure Codes for Excluded Elements. These measures shall be taken for each Excluded Element. Because of the unique nature of each Excluded Element, it is not possible to give detailed requirements for the nature of these equivalent measures. The general requirements for equivalent measures (also known as equivalency) shall be as follows:


·         Documentation for Excluded Elements shall include all of the following in addition to the documentation required by Part 1: Section 1.5 Required Documentation of this Supplement:

o   Reason why the engineering design requires that each Excluded Element cannot fully comply with selected Code of Record.

o   Specific Code requirements that cannot be met.

o   Calculations as required by Code, sound engineering principles, and the engineering design.

o   Specifications for special examinations or inspections if applicable.

o   Specific measures taken.

·         Measures taken to ensure a level of safety equal to or greater than that required by the most applicable ASME Pressure Code can include:

o   Extensive detailed analysis

o   Protective barriers

o   Secondary containment

o   Specialized testing

o   Protection of thin sections from accidental damage

o   Administration controls

·         The duties of organizations defined by ASME BPVC for vessels that cannot fully meet the requirements of the ASME BPVC shall be as follows:

o   The DA and System Owner shall assume the duties of the Owner/User

o   The DA shall assume the responsibilities of the Manufacturer

o   The duties of the Inspector shall be assumed by the “Owners Inspector” defined in Part 1: Section Responsibilities Derived from ASME B31 Piping Codes.

·         A Peer Review of each Excluded Element shall be performed. Complete Form PS-3.


The above requirements shall also apply to any component constructed by agencies other than Jefferson Lab. This includes the requirement for a Peer Review(s).


The DA is encouraged to consult other Jefferson Lab DAs for assistance, guidance and arbitration.  The DA may request both formal and informal guidance from the Pressure Systems Committee.










QA/CI Dept.

PS Committee/Chair