The fluids flowing through many pipelines are two phase, i.e., a mixture of liquid and gas. Ideally the two phases separate out with the liquid at the bottom section of the pipe. The two phases flow together to a processing facility that separates the two phases. In practice, however, the two phases often travel at different rates which means that they can form slugs whereby the composition of the stream at different sections is almost all liquid or almost all vapor.
Safety Moments are short stories or anecdotes that illustrate some aspect of personal or process safety. Generally they feature a near miss or foolish event that had the potential to be much worse than it was. They can be used to start a meeting or a task assignment.
The material in this article has been extracted from the book Plant Design and Operations.
After a piece of equipment or piping that operates under pressure has been opened and then reassembled (buttoned up) it must be pressure tested before being put back into service.
The material in this article is extracted from Chapter 2 of the 2nd edition of book Plant Design and Operations.
When developing the layout for a facility it is very important to ensure that personnel can move around quickly and safely using stairways, ladders, platforms and ramps. They should also be able to use the stairways and ladders to move maintenance equipment and tools, as needed and also to evacuate the facility during an emergency.
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.)