Equipment Piping Process Safety Management

Process safety programs require that all equipment be designed, operated and maintained to the highest standards. In practical terms this requirement means that if the equipment and piping always retains its integrity, i.e., if it does not leak, then then highly hazardous materials will not be released. (The term used by OSHA — Mechanical Integrity — is too limiting; integrity programs should incorporate instrumentation and other non-mechanical items. The phrase ‘Asset Integrity’ is a better choice. ).

Piping and valves have their own topic page.

The following is a list of the typical equipment covered by a process safety asset integrity program.

  • Pressure Vessels and Columns
  • Storage Tanks
  • Pumps
  • Compressors
  • Turbines
  • Heat Exchangers
  • Air-Cooled Exchangers
  • Cooling Towers
  • Fired Heaters
  • Flares / Blowdown
  • Boilers
  • Internal Combustion Engines
  • Electrical Equipment
  • Buildings

Regulations, Codes and Standards

There are many regulations, codes and standards to do with the mechanical integrity element of process safety management programs. Some of the key standards-setting bodies are:

  • American Chemistry Council / Responsible Care®
  • American National Standards Institute (ANSI)
  • American Petroleum Institute (API)
  • American Society of Mechanical Engineers (ASME)
  • International Organization for Standardization (ISO)
  • National Fire Protection Association (NFPA)

In the United States important process safety management regulations are published by:

  • The Environmental Protection Agency (EPA)
  • The Occupational Safety & Health Administration (OSHA) 
  • The Bureau of Safety and Environmental Enforcement (BSEE)

Articles and Safety Moments

Further information and guidance to do with this topic is available at the publications shown below.


Copyright © Ian Sutton. 2018. All Rights Reserved.


Safety Moment #44: Slug Catchers

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 Moment #7: No One There

A contractor was dewatering a 10 mile section of pipe after a hydrostatic test. He was using a foam pig that was pushed along by compressed air to displace the water. The water was removed from a 12" bypass line. The pig got stuck somewhere in the line it was decided to increase the pressure on the upstream side of the pig to 400 psig (28 barg). Downstream of the restriction the line was open, as shown. The differential force on the pig was almost 0.5 million pounds (2,200 kilonewtons).

With that kind of force behind it the pig was going to move.

Stairways and Ladders

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.

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.

Equipment Isolation Methods

Isolation Methods

Positive isolation methods are those which remain effective even if there is equipment failure or operator error. These techniques apply not only to vessels, piping and tanks but also to pneumatic and hydraulic equipment.

The sketch shows some of the various isolation techniques that can be used to protect workers in the process industries. The process containing toxic or flammable chemicals under pressure is on the left; the open system, where the workers are present, is on the right. The order is from the least to the most secure.

Siting and Layout of Process Facilities

Siting

Siting and Layout: The words ‘siting’ and ‘layout’ are often used interchangeably, but, strictly speaking, they have different meanings. Siting is concerned with the location of a facility. For example, if a company is planning on building a new chemical plant its management may consider the relative merits of sites in Texas, Mexico or China. Layout, on the other hand, is to do with the locations of equipment, piping and buildings at the selected site and how they connect with one another.