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Improving Global Quality of Life
Through Optimum Use and Innovation of Welding and Joining Technologies
general investment climate, including that created by economic and ecological pressures. A listing of the
types of pressure equipment (PE) in PE technology terms does not convey much more information to the
non-expert than the encompassing term PE itself: “pressure vessels, piping, accessories and assemblies
thereof operating where pressure creates a decisive hazard, with an allowable pressure above some specific
value, typically 0.5 bar”.
A listingof PE types inprocessengineering termsdoesgiveabetterpicture: accumulator (hydraulic, pneumatic,
steam), air cooler, air heater, air receiver, autoclave, bioreactor, boiler (biomass, black liquor, hot water,
power, recovery, steam, warm water, waste heat), chiller, column (absorption, air separation, distillation,
extraction, reaction), condenser, converter, cooler (back, inter, quench), cowper, deaerator, dehumidifier,
dephlegmator, desalinater, drier, economiser, evaporator, extractor, fermenter, flash vessel, gasifier, heater
(
feedwater, immersion, super), liquifier, preheater, reboiler, recuperator, refluxer, refrigerator, regenerator,
separator, silencer, steam reformer, sterilizer, stirring vessel, storage vessel, stripper, superheater, valve
(
blowdown, check, safety, shutoff, stop, vent), vaporiser, to list just the more important ones. Piping
may also be taken to include pressure pipelines. Gas cylinders are further examples – they may be static,
transportable, fired or unfired. The picture this listing conveys is that of an old industry, with a high degree
of specialisation and standardisation.
This picture is correct. PEI is an old industry, albeit a substantial component of industry as a whole – in the
European Union alone the annual turnover exceeds 86 billion Euro. It is a successful industry, with a good
safety record. Failures do occur, but most of them are caused by human errors, and/or result from “money
saving” issues, like reduced inspection frequency or saving shut-down times. Operator error and poor
maintenance account for 30 - 50% of incident causes, faulty design or fabrication for only a few percent. The
success was made possible by successful achievements in welding technology, and of testing methods and
equipment.
The success of the PEI is, at the same time, the cause of some of its present problems. For each frequently
occurring problem, at least one solution has been developed and embedded in codes and standards. These
solutions which are quite good and correct, are frequently overly conservative. Too often, however, incorrect
solutions have been “calibrated”, to achieve a usable recipe, often by usage of another inconsistent and
confusing “adaptation factor”. The success of the PEI is also the cause of its inherent resistance to change,
especially in the relevant codes and standards. Everyone in the industry is used to their local codes and
standards and knows that they lead to reasonable results. Equally, however, the background knowledge is
often vague, buried in records, or lost altogether.
9.5.1
Future of the industry
There are signs for concern:
The casting in stone of present national rules by creating lists of codes and standards which conform
to a common international standard with (only) requirements of what a standard should look like.
The reported pressure by inspection bodies on users to specify national rules, in order to be allowed
more economic in-service inspection intervals.
The noticeable resistance by manufacturers to using new design methods, because of “good
experience” with the old ones. This argument is seriously flawed, neglects the fact that equipment
is hardly ever used at its design limits and neglects the statistical nature of failures.
Advancements in the Pressure Equipment Industry towards global unified rules of technology are likely,
even in the near future, but they will require a common effort, and, especially, well-trained personnel
and continuing professional development, a possible cause of problems in countries with long established
industries and traditional attitudes.
