Pressure vessels are called vessels and equipment with an internal pressure higher than the 0,5 bar. The definition of pressurized equipment includes all kinds of pressurized containers and associated pipe systems, safety systems and pressurized accessories. Flanges, couplings, nozzles, supports, lifting eyebolts and similar parts on the pressure equipment are also included in this definition.
A large number of pressure vessels are provided with a number of devices which reduce the pressure completely or to a limit, such as safety valves, bursting discs, lapping bars or controlled pressure reducing systems, to prevent potential hazards if the prescribed pressure values are exceeded. In some pressure vessels, there are automatic systems that automatically switch on when the specified pressure limit is exceeded and allow the elimination of the failure and stop their activities partially or completely. Pressure and temperature switches, fluid level switches or all kinds of safety measuring, control and regulating devices are examples of these systems.
Examples of pressure vessels include:
- Heating (hot water) boiler
- Compressor and air tank
- Pressure tank and expansion tank
- Steam boiler
- LPG storage tank
- Hot water boiler
- Hot oil boiler
- Industrial gases storage tank
- Land tanker
- Tank for liquefied petroleum gases
- Pressure vessel safety device
Various gas cylinders, pipelines, cryogenic tanks, hydraulic fluid circuits, pneumatic fluid circuits and cooling units can be added to these examples.
The greatest possible hazards for pressure vessels include explosion, fragmentation, suffocation and poisoning, explosion and fire, and chemical and thermal burns. These dangers are great hazards to the health and safety of both the workers in production and the people using them.
Control and Inspection Principles of Pressure Vessels
Many legal arrangements have been made to prevent the dangers described above and a number of sanctions have been introduced for businesses. The first of these regulations is the Regulation on Health and Safety Conditions in the Use of Work Equipment issued by the Ministry of Labor and Social Security. According to the annex (Annex-III) of this regulation explaining the issues related to maintenance, repair and regular inspections, the pressure vessels are essentially hydrostatic tests. These tests shall be carried out at times 1,5 times the operating pressure and not exceeding one year unless there are any other requirements in the relevant standards. If hydrostatic testing cannot be carried out due to the characteristics of the pressure receptacle or a mandatory operating condition, tests may also be carried out by non-destructive testing methods mentioned in the standards instead of hydrostatic testing. However, at the end of the tests, the situation must be included in the report to be issued together with the reasons.
Other regulations issued for the regular inspection of pressure vessels and installations are:
- Pressure Equipment Directive (Published in January of 2007)
- Portable Pressure Equipment Directive (Published in December of 2012)
- Regulation on Simple Pressure Vessels (Published in December 2006)
The control and inspection procedures to be carried out shall be carried out in accordance with the criteria specified in the relevant standards, without prejudice to the provisions of these legal arrangements.
Periodic inspections of pressure vessels and installations shall be carried out only by mechanical engineers, machine technicians or high technicians. If inspections are to be carried out according to non-destructive testing methods, inspections may only be carried out by mechanical engineers, machine technicians or technicians trained in accordance with the TS EN 473 standard.
As many test and inspection organizations TÜRCERT Technical Control and Certification Inc. performs regular inspections and inspections of pressure vessels.