# Pressure Vessel Pro vs Optical Surface Recognition

The clearest difference is price: Optical Surface Recognition at Free against Pressure Vessel Pro's $5.99. Optical Surface Recognition also leads on rating (5.0 vs 4.5) and update cadence (every 2 weeks vs every 5 months). On ratings volume, ads, in-app purchases and device support there is nothing between them.

Optical Surface Recognition is free to download; Pressure Vessel Pro costs $5.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Optical Surface Recognition holds the better App Store score, 5.0 against 4.5. Both are backed by a comparable volume of ratings — 2 and 1 respectively.

Pressure Vessel Pro ships an update every 5 months, Optical Surface Recognition every 2 weeks. The most recent releases landed on October 5, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Pressure Vessel Pro | Optical Surface Recognition |
| --- | --- | --- |
| Price | $5.99 | **Free** |
| Rating | [4.5 (2 ratings)](https://appshunter.io/ios/app/pressure-vessel-pro/id535696875/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/optical-surface-recognition/id1480828202/reviews)** |
| Number of ratings | **2** | 1 |
| Positive reviews | 33.3% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 2 weeks** |
| Monetization | Paid | **Free** |
| Size | 10 MB | 17 MB |
| Requires iOS | 12.0 | 12.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [J.R.Hobbs](https://appshunter.io/developer/395110523) | [Engineering Director, Inc.](https://appshunter.io/developer/1480828201) |

## What reviewers say

### Pressure Vessel Pro

[App page](https://appshunter.io/ios/app/pressure-vessel-pro/id535696875)

Perform essential pressure vessel stress calculations with ease. Input dimensions for various tank geometries and instantly get results, including detailed formulae and ASME code compliance. Generate and share PDF reports with schematics.

**Highlights:** Pressure vessel stress calculations, ASME Boiler & Pressure Vessel Code compliance, Support for vertical, horizontal, and spherical tanks, Component stress calculations (cylinders, heads), Generate and share PDF reports, Flexible unit system (Metric/English), Save multiple calculation cases

**Features:** Vision Pro support

**In-app purchases:** none


### Optical Surface Recognition

[App page](https://appshunter.io/ios/app/optical-surface-recognition/id1480828202)

This utility app uses computer vision to scan surfaces for signs of corrosion on various metal types. It allows users to capture photos and record videos of detected corrosion, saving them with a proprietary score.

**Highlights:** Detects corrosion on various metal surfaces, Scans flat metal, nails, bolts, signs, poles, grates, Captures photos with corrosion score, Records videos with corrosion score, Saves media to device photo roll

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Pressure Vessel Pro free?

Pressure Vessel Pro costs $5.99, with no in-app purchases.

### Is Optical Surface Recognition free?

Optical Surface Recognition is free to download, with no in-app purchases.

### Which has better reviews, Pressure Vessel Pro or Optical Surface Recognition?

Optical Surface Recognition is rated higher. Pressure Vessel Pro averages 4.5 out of 5 from 2 ratings, while Optical Surface Recognition averages 5.0 from 1 ratings.

### Do Pressure Vessel Pro or Optical Surface Recognition have ads?

Neither Pressure Vessel Pro nor Optical Surface Recognition shows ads.

### Which is updated more often, Pressure Vessel Pro or Optical Surface Recognition?

Pressure Vessel Pro ships an update every 5 months, and Optical Surface Recognition every 2 weeks. Most recently, Pressure Vessel Pro was updated on October 5, 2026 and Optical Surface Recognition on October 7, 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.*