Lesson 4 - Steam Technology
This lesson takes a closer look at steam technology. It explores the generation of steam in boilers, as well as the distribution system and its components. It also considers the legal requirements associated with steam technology.
Boiler Safety
Boilers contain substantial amounts of hot water and steam, both of which are under pressure. Any failures can result in serious injuries and deaths, as well as damage to equipment and serious disruptions to production.
The Boiler Explosions Bill of 1882 reported that “one boiler explosion occurred every week, and one person was killed, and two injured, more or less, by a boiler explosion every four days”.
Over a hundred years ago, when boilers were exploding fairly regularly, there was a theory that it was due to the water breaking down into explosive components. Today, we know that this is not the case. Most explosions can be attributed to ‘boiling liquid expanding vapour explosions’ (BLEVE). A boiler contains saturated water at an elevated pressure. If the vessel fails, the pressure drops, and the liquid is almost instantly vaporised. This is a bit like opening a can of carbonated drink after you have given it a shake. Boilers are subject to regulations and design codes, depending on where they are situated. The American Society of Mechanical Engineers (ASME) introduced standards relating to boiler and pressure vessel design and construction in 1914, when it first published the ASME Boiler and Pressure Vessel Code. EN 19253 is a commonly used standard in Europe, according to which boilers are manufactured.
Boilers and ancillary equipment are subject to statutory inspections at set intervals. The frequency of these inspections will usually be agreed with your company’s insurers, but they often occur every 12-14 months. Written records must be kept of all work carried out on any part of the steam system, and a ‘permit-to-work’ system must be operational before anyone is allowed to work on a steam system. These inspections check the integrity of the vessel and tubes, as well as the operation of all the safety devices on the boiler.
What would you consider to be essential safety devices and systems on a boiler?
Give yourself 5-10 min to think about this, and then click ‘Next’ to continue with this lesson.