OSHA 1910.119 specifies that a mechanical integrity program must cover the following equipment:

• Pressure vessels and storage tanks

• Piping systems including components such as valves

• Relief and vent systems and associated devices

• Controls including monitoring devices and sensors, alarms and interlocks

• Pumps and compressors.

The language of this element of the standard seems too stiff and vague perhaps more useful to a courtroom lawyer than a practicing engineer working within a chemical plant. No doubt, the standard was intended to cover all components that handle highly hazardous materials. When the standard mentions pressure vessels and storage tanks, it no doubt included much more. Surely the standard meant to include reactors, filters, furnaces, boilers, other heat exchangers, surge bottles, knock-out pots, and other smaller miscellaneous containers common within the industry even if they were designed below 15 psig (104 kPa gauge) or not a storage tank. When piping is mentioned, it no doubt meant the associated expansion joints, hoses, tubing, supports, and so forth. When the standard mentions relief and vent systems, it no doubt meant ancillary equipment such as scrubbers, flare stacks, incinerators, and similar equipment found on such headers.

Assuming that the original equipment design was acceptable, then the requirement for inspection, testing, and correction of the deficiencies is the heart of the mechanical integrity standard. Any inspection and testing procedures used must follow the applicable manufacturer's recommendations and/or the generally accepted good engineering practices, guides, codes, as well as internal standards. The standard also...