# Pypley — Pipe Flow Rate Calculator

> Pipe flow rate, pressure drop, and pump performance calculator for engineers. (iPhone/iPad app by Ali Mohammed.)

- Source: https://appshunter.io/ios/app/pypley/id1540444278 (this page in markdown: same URL + `.md`)
- Developer: [Ali Mohammed](https://appshunter.io/developer/1540444280)
- Category: Utilities, Productivity
- Price: $2.99
- Rating: 1.00/5 from 1 App Store ratings · 6 written reviews indexed
- Age rating: 4+
- Requires: iOS 13.0 · 4 MB
- Languages: English
- Released: 2020-11-15
- Data updated: 2026-06-25
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/pypley/id1540444278/reviews.md

## What is Pypley?

Pypley calculates flow rate, pressure drop, and pump performance for circular pipe systems with Newtonian liquids. Build serial pipe systems using a pump database, fittings, and valves, with support for custom pumps and fittings stored via iCloud. Designed for hydraulic and process engineers, Pypley supports early-stage design and quick estimations.

Key Features:

* Converts all project parameters between Metric and US Imperial units.
* Calculates flow rate, pipe velocity, and pressure drop in pipes.
* Generates pressure loss tables for fittings and pipes in the system.
* Includes native and customizable pump database.
* Adjusts pump performance via speed (RPM) and impeller diameter.
* Plots pump and system performance curves.
* Computes K values for fittings using 3K and 2K methods.
* Determines Reynolds number for each pipe diameter.
* Calculates pipe friction factor using the Colebrook equation.
* Reports pump discharge pressure and pressure at each pipe’s start.
* Evaluates NPSHr and NPSHa to assess pump cavitation risk.
* Supports custom fitting lists with Kv/Cv coefficients or pressure/flow data.
* Detects negative pressure in pipelines.
* Identifies when centrifugal pumps reach maximum flow capacity.
* Organises projects chronologically, with newest first.
* Provides an expanded pipe material library with enhanced data.

Pypley is a design tool for hydraulic and process applications, ideal for initial designs or rapid calculations. Note: Pypley does not support parallel or network flow analysis.

Disclaimer: While we strive for accuracy and will address any issues, the developer is not liable for errors or omissions in Pypley’s calculations.

## Key features

- Flow rate and pressure drop calculation
- Customizable pump and fitting database
- Metric/Imperial unit conversion
- Pump performance curve plotting
- Cavitation risk assessment (NPSH)
- Reynolds number and friction factor calculation

## Recent user reviews (6 of 6)

All indexed reviews: https://appshunter.io/ios/app/pypley/id1540444278/reviews.md

### 1/5 — I would purchase this in a heartbeat, if…

*2024-08-29*

I was able to add pipe data and I could enter a negative value for elevation below pump centerline. Dead in the water after the first two minutes of trying to use this app.

**Developer response:** Thank you for your feedback, and I’m sorry to hear about your experience. As an engineer, this app started as a personal project, and I realize my initial approach might have made it challenging for others to use. I’m currently working on an update to make navigation more intuitive and address the issues you mentioned. I’m also putting together a quick two-minute tutorial video that will explain both the current version and the upcoming changes. I genuinely appreciate your patience and hope you’ll find the app more user-friendly with these improvements. Your feedback is invaluable as I continue to refine and improve it.

### 4/5 — Very useful

*2022-08-09, version 3.21*

As a mechanical engineer I constantly need to verify hydraulic pipe sizing and pump capacity. So I was always looking for something that can easily cross check my work like a second eye and this application is amazing in this regard. I just wish if the pumps selection are actual pumps from the market so you can just pick your selection and quickly check things in and that’s why I went for 4 starts instead of 5 :) .

### 4/5 — Very detailed application

*2021-08-12, version 3.1*

I have been looking for an application that can calculate flow rate of fluids with different densities and viscosities and this one does it.

### 5/5 — Great App

*2020-11-19, version 1.0*

Definitely worth spending some time in the tutorials. App very easy to use and accurate results. I would definitely recommend.

### 5/5 — Finally a simple app to solve a big problem

*2020-11-18*

Simple and easy to use

### 5/5 — Great App

*2020-11-18, version 1.0*

Recently downloaded this app to help with general pipework calculations. Can’t fault it 5⭐️

## Frequently asked questions about Pypley

### What is Pypley used for?

Pypley is a design tool for hydraulic and process applications. It calculates flow rate, pressure drop, and pump performance for circular pipe systems with Newtonian liquids, aiding in early-stage design and quick estimations.

### What kind of pipe systems does Pypley support?

Pypley supports serial pipe systems with Newtonian liquids. It does not support parallel or network flow analysis.

### Can I add my own pumps and fittings to Pypley?

Yes, Pypley allows you to store custom pumps and fittings via iCloud. You can also support custom fitting lists with Kv/Cv coefficients or pressure/flow data.

### Does Pypley support different units of measurement?

Yes, Pypley converts all project parameters between Metric and US Imperial units, making it versatile for different engineering standards.

### How does Pypley help assess pump issues?

Pypley evaluates NPSHr and NPSHa to assess pump cavitation risk. It also detects negative pressure in pipelines and identifies when centrifugal pumps reach maximum flow capacity.

### What is the price of Pypley?

Pypley is a paid application, priced at $2.99. It does not have in-app purchases or advertisements.

### How often is Pypley updated?

The latest version of Pypley is 4.0, last updated on September 16, 2025. This indicates a relatively active development cycle for the application.

### What devices is Pypley available on?

Pypley is supported on iPhone and iPod devices. It is rated for ages 4 and up.

## Version history (last 5 releases)

### 4.0 — 2025-09-16

* Converts all project entries between US and Metric units.
* Added in-app guidance for easier navigation and use.
* Resolved bugs to prevent unexpected app crashes.
* Projects now saved in chronological order, with newest first.
* Updated material library with additional entries and improved data.

### 3.21 — 2022-04-23

*Improving the UI to be more user friendly.
*fixing a problem with negative pressure detection.
*fixing a bug in custom fittings number.
*fixing a bug that can cause the app to crash.

### 3.2 — 2022-04-19

*Improving the UI to be more user friendly.
*fixing a problem with negative pressure detection.
*fixing a bug in custom fittings number.

### 3.1 — 2021-07-31

*Major user interface update based on valuable user feedback.
*Fixing a minor input error that can cause the app to crash.

### 3.0 — 2021-07-19

Major update for user interface, which is based on users feedback.
The new interface simplify the experience to a level that not tutorial is needed.

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## Related topics

[pypley](https://appshunter.io/ios/topics/pypley)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-25.*