This hazard classification applies to working with pressure vessels and systems.  Other hazard classifications and associated controls may apply to experiments in this hazard class.

Experiments involving previously reviewed hazard controls are categorized as medium risk experiments.

Experiments involving new equipment, processes or materials, or modified hazard control schemes are categorized as high risk experiments.

Engineered Controls – The establishment of applicable controls in accordance with the ASME (American Society of Mechanical Engineers) Boiler and Pressure Code, ASME B31 Pressure Piping Code, and applicable federal, state, and local codes.  Verify vessel is stamped with an ASME Code Symbol or allowable compressive stresses calculated using ASME Code Case 2286, July 17 1998.  Verify that pressure relief devices have ASME "UV" certification or documentation of operability tests demonstrating function and flow capacity is available.  Pressure relief device should be inspected and tested under current NBIC.  Piping/tubing should be compliant with operating temperature and pressure simultaneously.

Procedural Controls – Inspections and examinations of materials, in-process fabrications, nondestructive tests, and acceptance tests.  Documentation of the history of the vessel must be recorded and filed.  The documentation must include design and operating parameters, testing requirements, repair history, and procedures.  The Argonne Pressure Safety Manual may be used as guidance when evaluating pressure system hazards.

Design Reviews and Equipment Inspections – Design drawings and calculations must be reviewed.  Competent pressure system safety personnel must review pressure systems.  Assistance may be obtained via the ANL Pressure Technology and Safety Committee (PTSC).  The information needed for the safety review of the pressure equipment can be found in the APS Documentation Requirements for Pressurized Experiment Apparatus

Training – Equipment manufacturer's guidelines, PTSC recommendations, operating procedures

Signs and Labeling – Identification of capacity, use, and limits of vessels

Personal Protective Equipment – safety glasses with side shields (ANSI Z87.1), safety shoes, protective clothing

Monitoring – None

Unless otherwise noted in the approved experiment safety plan, the PSC Deputy Associate Laboratory Director of Operations delegates the authority to authorize an experiment in this hazard class to a member of the APS Experiment Safety Review Board and resident beamline personnel having the authority to authorize experiments as listed in the ESAF system.  Approval by both the host beamline and APS Experiment Safety Review Board are mandatory prerequisites for experiment authorization.

The PSC Deputy Associate Laboratory Director of Operations delegates responsibility for verifying that required controls are in place to the experiment On-Site Spokesperson and Beamline Management.

ANL Pressure Safety Manual, Volume 1 (2022) (Internal link)

ANL Pressure Safety Manual, Volume 2 (2022) (Internal link)

Contact the APS User Safety Program with any questions or if the internal links are not working properly.