# Orifice Flow vs Parker PDN

The clearest difference is price: Parker PDN at Free against Orifice Flow's $3.99. Parker PDN also leads on rating (5.0 vs 4.0) and update cadence (every 3 months vs every 12 months). On review sentiment, ratings volume, ads and in-app purchases there is nothing between them.

Parker PDN is free to download; Orifice Flow costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Parker PDN holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

Orifice Flow ships an update every 12 months, Parker PDN every 3 months. The most recent releases landed on October 30, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | Orifice Flow | Parker PDN |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | [4.0 (1 ratings)](https://appshunter.io/ios/app/orifice-flow/id479581349/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/parker-pdn-legacy/id995188136/reviews)** |
| Number of ratings | 1 | 1 |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 12 months | **Every 3 months** |
| Monetization | Paid | **Free** |
| Size | 1 MB | 2 MB |
| Requires iOS | **14.3** | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Kaup Shenoy Associates](https://appshunter.io/developer/460148822) | [Technology Solutions of Michigan](https://appshunter.io/developer/584020901) |

## What reviewers say

### Orifice Flow

[App page](https://appshunter.io/ios/app/orifice-flow/id479581349)

Calculate fluid flow rates in pipes and conduits using orifice plates. Supports common industrial fluids and custom fluid properties, with adjustable units and orifice types. Ideal for engineers and designers.

**Highlights:** Fluid flow rate computation, Supports 15 common industrial fluids, Custom fluid property input and saving, Multiple orifice plate types, Adjustable units (SI/USCS), Detailed computation model documentation

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Parker PDN

[App page](https://appshunter.io/ios/app/parker-pdn-legacy/id995188136)

This utility app is being retired and users are directed to download a new, updated application. The new app offers enhanced features and support for pneumatic tools.

**Highlights:** Retiring legacy application, Directs to new app, Pneumatic tool support, Updated features

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Orifice Flow free?

Orifice Flow costs $3.99, with no in-app purchases.

### Is Parker PDN free?

Parker PDN is free to download, with no in-app purchases.

### Which has better reviews, Orifice Flow or Parker PDN?

Parker PDN is rated higher. Orifice Flow averages 4.0 out of 5 from 1 ratings, while Parker PDN averages 5.0 from 1 ratings.

### Do Orifice Flow or Parker PDN have ads?

Neither Orifice Flow nor Parker PDN shows ads.

### Which is updated more often, Orifice Flow or Parker PDN?

Orifice Flow ships an update every 12 months, and Parker PDN every 3 months. Most recently, Orifice Flow was updated on October 30, 2026 and Parker PDN on October 13, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*