Editing Fuel injection (section)

=== Common-rail injection systems ===
{{Main|Common-rail injection}}

In a common-rail system, fuel from the fuel tank is supplied to a common header (called the [[Hydraulic accumulator|accumulator]]), and then sent through tubing to the injectors, which inject it into the combustion chambers. The accumulator has a high-pressure relief valve to maintain pressure and return the excess fuel to the fuel tank. The fuel is sprayed with the help of a nozzle that is opened and closed with a [[Solenoid valve|solenoid-operated]] [[needle valve]].<ref>Helmut Tschöke, Klaus Mollenhauer, Rudolf Maier (ed.): Handbuch Dieselmotoren, 8th edition, Springer, Wiesbaden 2018, {{ISBN|978-3-658-07696-2}}, p. 289</ref> Third-generation common-rail diesels use [[Piezoelectric motor|piezoelectric]] injectors for increased precision, with fuel pressures up to {{convert|300|MPa|psi|abbr=on|lk=on|disp=or}}.<ref>Helmut Tschöke, Klaus Mollenhauer, Rudolf Maier (ed.): Handbuch Dieselmotoren, 8th edition, Springer, Wiesbaden 2018, {{ISBN|978-3-658-07696-2}}, p. 1000</ref>

The types of common-rail systems include ''air-guided injection''<ref name="van Basshuysen_62">Richard van Basshuysen (ed.): Ottomotor mit Direkteinspritzung und Direkteinblasung: Ottokraftstoffe, Erdgas, Methan, Wasserstoff, 4th edition, Springer, Wiesbaden 2017, {{ISBN|978-3-658-12215-7}}, p. 62</ref> and ''spray-guided injection''.<ref name="van Basshuysen_62" />