menu move to sidebar hide Navigation Main page Contents Current events Random article About Wikipedia Contact us Contribute Help Learn to edit Community portal Recent changes Upload file Special pages Search Search Appearance Donate Create account Log in Personal tools Donate Create account Log in Contents move to sidebar hide (Top) 1 Explanation 2 Liquid chromatography 3 See also 4 References Toggle the table of contents Back pressure 5 languages العربية Deutsch Italiano 日本語 Русский Edit links Article Talk English Read Edit View history Tools Tools move to sidebar hide Actions Read Edit View history General What links here Related changes Upload file Permanent link Page information Cite this page Get shortened URL Switch to legacy parser Print/export Download as PDF Printable version In other projects Wikidata item Appearance move to sidebar hide From Wikipedia, the free encyclopedia (Redirected from Backpressure ) Force opposing the flow of fluid through pipes For the routing algorithm, see backpressure routing . Back pressure (or backpressure ) is the term for a resistance to the desired flow of fluid through pipes. Obstructions or tight bends create backpressure via friction loss and pressure drop . [ 1 ] In distributed systems in particular event-driven architecture , back pressure is a technique to regulate flow of data, ensuring that components do not become overwhelmed. [ 2 ] Explanation [ edit ] Two similar pipings with same pressure distance and head. The second pipe contains some obstructions for flow resulting in less discharge. A common example of backpressure is that caused by the exhaust system (consisting of the exhaust manifold , catalytic converter , muffler and connecting pipes ) of an automotive four-stroke engine , which has a negative effect on engine efficiency , resulting in a decrease of power output that must be compensated by increasing fuel consumption . [ 3 ] [ 4 ] In a piston-ported two-stroke engine , however, the situation is more complicated, due to the need to prevent unburned fuel/air mixture from passing right through the cylinders into the exhaust. During the exhaust phase of the cycle, backpressure is even more undesirable than in a four-stroke engine, as there is less time available for exhaust and the lack of pumping action from the piston to force the exhaust out of the cylinder. However, since the exhaust port necessarily remains open for a time after scavenging is completed, unburned mixture can follow the exhaust out of the cylinder, wasting fuel and increasing pollution. This can only be prevented if the pressure at the exhaust port is greater than that in the cylinder. Since the timing of this process is determined mainly by exhaust system geometry, which is extremely difficult to make variable, correct timing and therefore optimum engine efficiency can typically only be achieved over a small part of the engine's range of operating speed. [ 5 ] [ 6 ] Liquid chromatography [ edit ] Back pressure is the term used for the hydraulic pressure required to create a flow through a chromatography column in high-performance liquid chromatography , the term deriving from the fact that it is generated by the resistance of the column, and exerts its influence backwards on the pump that must supply the flow. Back-pressure is a useful diagnostic feature of problems with the chromatography column. [ 7 ] Rapid chromatography is favoured by columns packed with very small particles, which create high back-pressures. [ 8 ] Column designers use "kinetic plots" to show the performance of a column at a constant back-pressure, usually selected as the maximum that a system's pump can reliably produce. [ 9 ] See also [ edit ] Exhaust pulse pressure charging Expansion chamber Scalar quantity References [ edit ] ↑ Shekhar, Ravi; Singh Dhugga, Paramvir; Malik, Kashish (2016). "CFD analysis of Back Pressure due to bend in exhaust Pipe of 4 stoke petrol engine" (PDF) . Int. J. Aerosp. Mech. Eng . 3 (4): 1– 3. ↑ Fundamentals of Software Architecture: An Engineering Approach . O'Reilly Media. 2020. ISBN 978-1-4920-4345-4 . ↑ Hield, Peter (2011). The effect of back pressure on the operation of a diesel engine (PDF) (Report). Defence Science and Technology Group . Archived (PDF) from the original on June 24, 2021. ↑ Kocsis, Levente-Botond; Moldovanu, Dan; Baldean, Doru-Laurean (2015). "The influence of exhaust backpressure upon the turbochargers boost pressure" . Proceedings of the European Automotive Congress EAEC-ESFA 2015 . Springer International Publishing . pp. 367– 374. ISBN 978-3-319-27276-4 . ↑ Blair, Gordon (1996). Design and Simulation of Two-Stroke Engines . SAE International . ISBN 978-1-56091-685-7 . Archived from the original on 25 October 2012. ↑ Dalla Nora, Macklini; Lanzanova, Thompson Diórdinis Metzka; Zhao, Hua (2016). "Effects of valve timing, valve lift and exhaust backpressure on performance and gas exchanging of a two-stroke GDI engine with overhead valves" (PDF) . Energy Conversion and Management . 123 : 71– 83. Bibcode : 2016ECM...123...71D . doi : 10.1016/j.enconman.2016.05.059 . ↑ Majors, Ronald E (2007). "Column Pressure Considerations in Analytical HPLC" . LCGC North America . 25 (11): 1074– 1092 . Retrieved 10 March 2022 . ↑ Berger, Terry A. (2022). "The evolution and current state of instrumentation for analytical supercritical fluid chromatography". Journal of Chromatography B . 1211 123478. doi : 10.1016/j.jchromb.2022.123478 . ISSN 1570-0232 . ↑ Neue, Uwe D. (2009). "Kinetic Plots Made Easy" . LCGC North America . 27 (11): 974– 983 . Retrieved 10 March 2022 . Retrieved from " https://en.wikipedia.org/w/index.php?title=Back_pressure&oldid=1352049482 " Categories : Engine technology Pressure Piping Two-stroke engine technology Hidden categories: Articles with short description Short description matches Wikidata This page was last edited on 1 May 2026, at 18:35  (UTC) . Page was rendered with Parsoid . Text is available under the Creative Commons Attribution-ShareAlike 4.0 License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy . Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. , a non-profit organization. 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