# PipeFall: Pipe & Drain Sizing — Slope, Fixture Units & DFU

> Slope, Fixture Units & DFU (iPhone/iPad app by ZHENGQIAO JIANG.)

- Source: https://appshunter.io/ios/app/pipefall-pipe-and-drain-sizing/id6773148982 (this page in markdown: same URL + `.md`)
- Developer: [ZHENGQIAO JIANG](https://appshunter.io/developer/1892168889)
- Category: Utilities, Reference
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 17.0 · 2 MB
- Languages: American English, French (France), German (Germany), Japanese, Korean
- Released: 2026-05-28
- Data updated: 2026-07-27
- User reviews in markdown: https://appshunter.io/ios/app/pipefall-pipe-and-drain-sizing/id6773148982/reviews.md

## What is PipeFall?

Tired of flipping through code books on the job just to size a drain?
PipeFall turns fixture counts and pipe runs into code-referenced sizes
in seconds.

Here's how it works: pick your code, add your fixtures or enter your run,
and PipeFall returns the minimum pipe size, the required slope, and a
pass-or-fail check against the exact table it used. Done. No accounts.
No uploads. No tracking. Everything happens on your iPhone.

Whether you're roughing in a bathroom, sizing a building drain, or checking
a trap arm before the inspector arrives, PipeFall is built to be the fastest
way to get the number right the first time.

It covers drainage fixture unit sizing, water supply sizing with Hunter's
curve, drainage slope and fall in every common format, vent and trap arm
checks, pipe offsets and rolling offsets, pipe volume and weight, and thermal
expansion. Every table is based on the 2021 International Plumbing Code, so
the sizes match what the inspector checks against. You can even set your
iPhone on the pipe and use it as a slope level, then send the reading
straight into the calculator.

Every result is referenced to the code table behind it, so you can always
show your work. Save jobs, group your calculations, and export a clean PDF
for the file or the client. PipeFall runs 100% offline — no data collection,
no ads, no sign-in.

3-day free trial, then $1.99/week. Cancel anytime.

Terms of Use: https://taxlite.net/pipe_fall/terms.html
Privacy Policy: https://taxlite.net/pipe_fall/privacy.html

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Weekly | $1.99 | per 7 days |
| Monthly | $4.99 | per month |
| Yearly | $29.99 | per year |

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Lifetime | $79.99 | one-time |



## Version history (last 2 releases)

### 1.1.0 — 2026-07-22

Storm drainage and fuel gas are here.

• Storm drainage — roof flow, storm drains, leaders and gutters (IPC Ch 11)
• Fuel gas pipe sizing — natural gas and propane, all five materials (2021 IFGC Table 402.4)
• Wet venting and combination waste & vent systems
• Parallel pipe cutbacks — keep a bank of pipes in step through an offset
• Water heater load, pump head, and expansion tank sizing
• Area, perimeter, and tank fill / drain times
• Pipe dimensions now cover 9 materials, from copper K through PEX
• Hanger spacing, cleanout rules, and fixture clearances added to Reference
• Capacity-used bar on drain sizing, so you can see the headroom

Fixed: the inside diameter listed for 1-1/4" PVC Schedule 40 was 1.380",
and is corrected to 1.360" per ASTM D1785. If you sized pipe volume,
velocity or pressure drop on 1-1/4" PVC in an earlier version, those
figures were about 3% off — worth re-running.

Every result still cites the table behind it.

### 1.0 — 2026-05-28

No release notes.

## More apps by ZHENGQIAO JIANG

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- [ReadAloud: Text to Speech](https://appshunter.io/ios/app/readaloud-text-to-speech/id6765783837)

All apps by ZHENGQIAO JIANG: https://appshunter.io/developer/1892168889

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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 2026-07-27.*