Mechanical integrity installation

Mechanical integrity An element of process safety focused on ensuring that equipment is designed, installed, and maintained to perform the desired function. 

Equipment used to process, store, or handle highly hazardous chemicals must be designed constructed, installed and maintained to minimize the risk of release. A systematic, scheduled, test and maintenance program is preferred over "breakdown" maintenance " that could compromise safety. Elements of a mechanical integrity program include 1) identification and categorization of equipment and instrumentation, 2) documentation of manufacturer data on mean time to failure, 3 ) test and inspection frequencies, 4) maintenance procedures, 5) training of maintenance personnel, 6) test criteria, and 7) documentation of test and inspection results. 

This section discusses inspection and maintenance practices and procedures that affect the mechanical integrity of flame arrester installations. 

These polytetrafulorothylene (PTFE) pumps along with the associated plastic expansion joints were installed, because the sponsors were blinded by the advantages. No one took the time to question their suitability in handling flammable liquids. The plastic pumps are just not fire-safe. They are frail in a fierce hydrocarbon fire. The presence of a containment material, such as plastic, can jeopardize the built-in mechanical integrity of the surrounding equipment. 

As stated in lEC 61611-1 ANSI/ISA-84.00.01-2004 Part 1 (lEC 61511-1 Mod), inspecting the SIS is different from proof testing. Whereas a proof test is ensuring the SIS will operate properly, a visual inspection is required to validate the mechanical integrity of the installation. 

This covers more than just maintenance training. All employees need to be aware of mechanical integrity issues. For example. Chapter 11 describes an accident that was caused by the installation of an incorrect gasket. This incident involved both an operator and a warehouse worker, both of whom needed training in mechanical integrity as it applied to their work. 

Figure 12.1 Mechanical integrity starts long before the equipment is being installed. Mechanical integrity starts with the design to appropriate codes, the fabrication to standards and the testing to codes. Mechanical integrity continues with routine inspections and tests per codes as well as maintenance. Ml does not end until the equipment is taken out of service.

A user approval process should assure that field equipment has an established history of performance in a similar operating environment and that its failure mechanisms are understood and accounted for in the design, operation, and mechanical integrity practices. ISA-TR84.00.04-1 Annex L provides guidance on the selection of SIF devices. An SIS must be sufficiently robust to meet the required SIL under operating environment conditions. For each installation, define the conditions that impact SIS equipment selection, such as ... 

This topic, the full name of which is Assurance of Quality and Mechanical Integrity of Critical Equipment, requires that procedures have to be in place and implemented so that critical equipment is designed, fabricated, installed, tested, inspected, monitored, and maintained in a manner consistent with appropriate service requirements, manufacturer s recommendations, or industry standards. Contractors should have programs in place to address the safety of their own critical equipment. 

Mechanical Integrity PSSR verifies maintenance task procedures are in place and workers have been trained on the tasks and applicable safe work practices. PSSR verifies equipment has been reviewed for placement in the mechanical integrity program and that it was designed and installed according to codes, standards, and manufecturers recommendations. 

High mechanical integrity to minimize mechanical damage during installation, maintenance, and service use... 

Mechanical Integrity Vessels and other equipment must meet existing codes and be inspected during manufacture and after installation. Appropriate procedures for maintenance must be developed and followed. 

The Mechanical Integrity element of PSM was also a critical issue as the temporary pipe had not been designed according to established engineering standards. Also, there must have been problems with the integrity or inspection program before the accident. After all, if the leak in the pressure vessel had not occurred, there would have been no need to install a bypass. 

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