Classification of Pressure Equipment

Technical equipment of group A and group B are considered designated pressure technical equipment (Annex No. 1 to Decree No. 508/2009 Coll.).

Group A

Letter a) heated or otherwise heated technical equipment with a risk of overheating, intended for steam production or for heating liquids whose temperature is higher than the boiling point at a pressure of 0.05 MPa:

• steam boilers with a nominal steam production rate exceeding 115 t/h (Class I),
• steam boilers with a nominal steam production rate exceeding 50 t/h up to and including 115 t/h, and liquid (hot water) boilers with a thermal output exceeding 35 MW (Class II),
• steam boilers with a nominal steam production rate exceeding 8 t/h up to and including 50 t/h, and liquid (hot water) boilers with a thermal output exceeding 5.8 MW up to and including 35 MW (Class III),
• steam boilers with a nominal steam production rate up to and including 8 t/h, and liquid (hot water) boilers with a thermal output up to and including 5.8 MW (Class IV).

Letter b) stationary pressure vessel that:

• does not contain hazardous gases, vapors, or liquids with a temperature higher than their boiling point at a pressure of 0.2 MPa, with a volume exceeding 10 liters, and whose product of the volume of the pressure technical equipment in liters and the maximum operating pressure in MPa (hereinafter referred to as “safety product”) is greater than 20 (200); this group also includes a vessel for steam production that is part of a work equipment, if it meets the specified parameters,
• contains hazardous gases or hazardous liquids at any temperature, whose maximum allowable pressure is greater than 0.05 MPa, with a volume exceeding 1 liter, and whose safety product is greater than 5 (50).

Letter c) pressure vessel for the transport of gases whose critical temperature is lower than 50 °C, or gases which at 50 °C have an absolute vapor pressure greater than 0.3 MPa (tankers).

Letter d) pressure vessel of a mobile water fire extinguisher, mobile water fire extinguisher with additives, mobile foam fire extinguisher, and mobile powder fire extinguisher.

Letter e) pipeline with a nominal pipe bore greater than DN 25 for the distribution of hazardous liquid with a maximum allowable pressure exceeding 1 MPa, whose product of the maximum allowable pressure in MPa and the nominal bore DN is greater than 200 (2,000).

Group B

Letter a) heated or otherwise heated equipment with a risk of overheating, intended for steam production with a nominal pressure up to and including 0.05 MPa, or for heating liquid at a temperature lower than the boiling point, with a nominal thermal output exceeding 100 kW (Class V).

Letter b) stationary pressure vessel that contains:

• non-hazardous gases, vapors, or liquids with a temperature higher than their boiling point at a pressure of 0.05 MPa, with a volume exceeding 1 liter, and whose safety product is greater than 5 (50); this group also includes a vessel for steam production that is part of a work equipment, if it meets the specified parameters,
• hazardous gases or hazardous liquids at any temperature, whose maximum allowable pressure is greater than 0.05 MPa, with a volume exceeding 1 liter, and whose safety product is greater than 2.5 (25).

Letter c) pressure vessel for the transport of gases whose critical temperature is lower than 50 °C, or gases which at 50 °C have an absolute vapor pressure greater than 0.3 MPa, such as cylinders and drums:

• cylinders with a volume greater than 0.5 liters, cylindrical or spherical in shape, equipped with a neck at one or both ends, including cylinders containing carbon dioxide dissolved in beverages (Class I),
• drums – welded cylindrical pressure vessels with a volume greater than 100 l, equipped with hoops (Class I).

Letter d) pressure vessel of a portable fire extinguisher and pressure vessel of a mobile CO2 fire extinguisher.

Letter e) pipeline:

• for the distribution of hazardous liquid with a maximum allowable pressure exceeding 0.05 MPa up to 1 MPa, whose product of the maximum allowable pressure in MPa and the nominal pipe bore DN is 200 (2,000) and greater,
• with water vapor as the working medium, whose product of the maximum allowable pressure in MPa and the nominal pipe bore DN is 350 (3,500) and greater, where the nominal pipe bore is greater than DN 100, regardless of expanded sections.

Letter f) safety accessories:

• that protect pressure technical equipment from exceeding the maximum operating pressure,
• ensuring monitoring and adherence to the operating temperature in pressure technical equipment where exceeding or falling below specified limits endangers their safety,
• ensuring monitoring of the level and exceeding its boundary limits in pressure technical equipment where exceeding or falling below specified limits endangers their safety,
• intended for automatic operation on steam and liquid boilers, for example, for automatic blowdown and descaling, regulation of flow, feedwater, and temperature of superheated and reheated steam and water.

Group C

Small pressure vessels, air receivers with a low pressure-volume product, hot water boilers with lower output, pipelines with smaller nominal bore, and other pressure equipment that does not meet the criteria for classification into group A or B.

Note: The classification of specific equipment depends on its technical parameters according to Annex No. 1 of Decree No. 508/2009 Coll.

Source: Annex No. 1 to Decree No. 508/2009 Coll.