The pressure conversion calculator tool is a practical way of converting an existing value into different other units. The units can be changed using specific conversion factors by using the calculator below.
The individual regulations for pressure equipment and pipework contain corresponding specifications for the use of the correct unit of pressure. The regulations permit different units, e.g. for calculations, if the principle of consistent application is observed through correct conversions..
The unit for the pressure in the International System of Units (SI): Pa
Other units for leakage rates are available in various regulations and standards. Conversions are possible (see above calculation programme for other conversions..
Definition: Pressure relative to atmospheric pressure, i.e. gauge pressure. As a consequence, vacuum is designated by a negative value; the unit bar is always used as gauge pressure.
General pressure unit use for PED and EN 13445/EN 13480 series: bar;
Note 1: bar is not an SI unit, but may be used with SI units and their multiples. The unit bar is always used as gauge pressure.
Note 2: The unit MPa is only permissible for calculation purposes; e.g. EN 13445-3;
Name plate and labelling marking: bar (for PS and PT)
Definition: Pressure above atmospheric pressure
Note: Full vacuum is a condition where the internal absolute pressure is 0 psi (0 kPa) and the external absolute pressure on the vessel is 15 psi (103 kPa)
The general unit for pressure according to ASME BPVC is the U.S. Customary Unit: psi (kPa)
Note: U.S. Customary, SI, or any local customary units may be used to demonstrate compliance with requirements (ASME BPVC Section VIII Div. 1 (UG-4)).
Name plate: Nameplate marking shall be in units consistent with the fabrication drawings for the component using U.S. Customary, SI, or local customary units (ASME BPVC Section VIII Div. 1 (UG-4)).
