Equivalent Lengths

Chapter from the Piping Design Guide.

EQUIVALENT LENGTHS — FITTINGS & VALVES

Equivalent Length of Fittings (ft of straight pipe)

Fitting Type	2"	4"	6"	8"	10"	12"
90° long-radius elbow	5.2	8.5	13	17	21	25
90° short-radius elbow	8.5	14	20	27	33	40
45° elbow	2.7	4.5	6.7	8.5	11	13
Tee — flow through run	3.5	5.5	8.5	11	14	17
Tee — flow through branch	10	17	26	34	43	50
Gate valve (full open)	1.1	1.8	2.8	3.5	4.4	5.2
Globe valve	29	48	73	95	120	140
Check valve (swing)	6	10	16	20	26	30
Ball valve (full bore)	0.6	1.0	1.5	2.0	2.5	3.0
Butterfly valve	3.5	6	9	12	15	18
Reducer (sudden contraction)	1.5	2.5	3.5	5.0	6.0	7.5
Expander (sudden enlargement)	2.5	4.0	6.0	8.0	10	12
Pipe entrance (sharp-edged)	2.5	4.0	6.5	8.5	10	13
Pipe exit	4.0	6.5	10	13	17	20

Reference: Crane TP-410, Flow of Fluids Through Valves, Fittings, and Pipe
Note: Values are approximate and based on schedule 40 pipe. Actual equivalent lengths vary by manufacturer. For critical applications (pump suction, relief valve inlet), use manufacturer-specific data or K-factor method.
K-factor method: h_L = K × v²/(2g) where K is the resistance coefficient from Crane TP-410.

Source: Piping_Design_Guide_v1.xlsx · sheet “Equivalent Lengths”

© 2026 Inflection Point Engineering, LLC. All rights reserved. The content of this page — including calculation methods, reference data, written analysis, interactive tools, and source code — is the intellectual property of Inflection Point Engineering, LLC and is protected under applicable copyright, trademark, and trade secret laws. Unauthorized reproduction, redistribution, modification, or derivative use in whole or in part is prohibited without prior written consent.

Disclaimer. This material is provided for informational and educational purposes only and does not constitute professional engineering advice. Calculations, reference data, and methodologies are based on published standards and accepted engineering practice but are not a substitute for engineering judgment, site-specific analysis, or review by a licensed Professional Engineer. Inflection Point Engineering, LLC makes no warranties, express or implied, regarding the accuracy, completeness, or fitness for a particular purpose of any content presented here, and shall not be liable for any direct, indirect, incidental, or consequential damages arising from its use. Users assume all risk associated with applying this content to real-world design, operations, or decisions.