Information on Pipe Pressure Drop Calculation Methods
This section lists some articles which give background information on the methods used for calculating pressure drops through pipe fittings and valves.
Click on the links below to read the articles.
- Pressure drop calculation methods for pipe fittings
Piping engineers often need to convert between equivalent lengths (Le/D) and resistance coefficients (K-values) when calculating pressure drops or flow rates through pipe fittings and valves. Here is a discussion on the relative merits of these methods and how to convert between them. - Tables of Equivalent Lengths for pipe fittings in plastic and steel pipe
The article above describes how to use the Equivalent Length Method, and this article gives the necessary data to apply the method for a wide variety of pipe fittings and valves for both plastic (PVC, CPVC, HDPE, GRP/FRP) and steel (commercial and spiral welded) pipe. - Pipe Entrance and Exit Losses Demystified
Virtually all fluid mechanics handbooks discuss the changes in pressure described by Bernoulli's Equation and also discuss the frictional losses at pipe entrances, exits and changes in pipe diameter. However, very few of them give much attention to how the Bernoulli pressure changes and the frictional losses interact, and some of the handbooks that do include examples of this are somewhat misleading.
This article takes a deep dive into the phenomena at play and considers the interplay between the Bernoulli and friction effects. Several worked examples are also given to illustrate the various situations.