Centrifugal pump
A centrifugal pump. It is drawn as a circle with the outlet line leaving it at a tangent from the top.
Easily confused with
How to read it
The centrifugal pump is the most common kind of pump. The DOE’s Mechanical Science handbook calls it the most common type in DOE facilities, and Kuphaldt’s Lessons In Industrial Instrumentation the most common pump design in the process industries. Inside is an impeller on a rotating shaft. The casing guides the liquid to the centre, or eye, of the impeller, the vanes throw it outward, and the volute around the edge collects it and sends it out through the discharge.
The DOE’s chart draws the pump as a circle with the inlet coming in at the centre and the outlet leaving from the top at a tangent, with variations on where the outlet leaves. That matches the path the handbook describes: in at the eye, out from the edge of the casing.
Also searched as: centrifugal pump p&id symbol, centrifugal pump symbol, pump symbol.
This explains what a symbol represents on a diagram. Companies vary the symbols, and a diagram's own legend sheet takes precedence.
Look-alikes
A circle with a zigzag through it is a heat exchanger. Fluid power diagrams, the hydraulic and pneumatic schematics in the DOE’s handbook, use different symbols: a pump there is a circle containing one or more arrowheads with their points touching it, solid for a hydraulic pump and hollow for a pneumatic Compressor.
Read next
- Next in P&ID symbolsCompressorA compressor, which raises the pressure of a gas and moves it on. Symbol charts draw it in several ways, one of them a trapezoid narrowing in the direction of flow.
- The same shape in African flagsFlag of EthiopiaEthiopia’s flag is green, yellow and red in equal horizontal stripes with a blue disc in the centre holding a yellow star of equal lines with yellow rays. Ethiopia’s Flag Proclamation makes the green labour, fertility and development, the yellow hope, justice and equality, and the red sacrifice and heroism for freedom and equality; the blue disc is peace and the star the unity of Ethiopia’s nations, nationalities and peoples.
More P&ID symbols
The same shape elsewhere
Browse symbols drawn with circles or lines.
Sources
- DOE Fundamentals Handbook: Mechanical Science, Volume 1 of 2, DOE-HDBK-1018/1-93, January 1993, U.S. Department of Energy (University of Cambridge Engineering Department mirror), Module 3, Pumps: Centrifugal Pumps
- DOE Fundamentals Handbook: Engineering Symbology, Prints, and Drawings, Volume 1 of 2, DOE-HDBK-1016/1-93, January 1993, U.S. Department of Energy (University of Cambridge Engineering Department mirror), Module 2: Components (Figure 15); Fluid Power P&IDs
- Lessons In Industrial Instrumentation, Tony R. Kuphaldt, version 2.33, 2024 (CC BY 4.0), Tony R. Kuphaldt (ibiblio.org), Chapter 27, Control valves, footnote 42
Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 9, 2026. How we research
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