The following articles provide information to do with the operation, maintenance and inspection of process facilities.

Contractors in the Process Industries

Contractors play a vital and increasingly important role in the design, construction, operation and maintenance of process and energy facilities, as can be seen from the chart shown below. It can be seen that, over the last twenty years or so, the number of contractor work hours has increased by about a fact of fifteen, whereas the number of hours worked by employees of the host companies has hardly doubled. (The offshore oil and gas industry is particularly reliant on contractors.)

Types of Maintenance

Process Safety Maintenance

Maintenance work usually falls into one of the following four categories:

  1. Repair;
  2. Condition-based maintenance;
  3. Scheduled maintenance; and
  4. Reliability-centered maintenance (RCM).

All but the first of these can be placed in the overall category of preventive or preventative (either spelling is acceptable) maintenance.

Confined Space Entry

Confined Space Entry

A Confined Space is a space which is large enough for a worker to enter but has limited openings for entry and exit and is not intended for continuous employee occupancy. Entry is considered to have occurred as soon as any part of the entrant's body breaks the plane of an opening into the space. Therefore it is not permissible, for example, to take a quick breath and to put one's head into a vessel for a quick look without having an entry permit.

Lockout Tagout Process Safety Management

Lockout / tagout systems are routinely used to protect workers when they are working with or close to hazardous systems. They are typically used in conjunction with the other isolation methods. Once a switch or valve is in the correct position it is locked so that it cannot be moved, and a 'Do Not Operate' tag is attached to it. (Valves are often chained in place, with the lock being used to secure the chain such that the valve handle cannot be moved.)

Safety Signs

Safety signs. The material in this post is extracted from Chapter 16 of the 2nd edition of the book Plant Design and Operations.

Guidance as to the types of signs and their meanings is provided below.


Prohibition signs mean "You must not" or "Do not do . . ." or "Stop". Signs of this type have a red circle, a white interior and a red bar, as illustrated in Figure 16.4.

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