# Silverson Conversion Tools vs Pressure Vessel Heads

The clearest difference is price: Silverson Conversion Tools at Free against Pressure Vessel Heads's $2.99. Silverson Conversion Tools also leads on update cadence (every 6 months vs every 56 months) and iOS requirement (8.0 vs 16.1). On ads, in-app purchases and device support there is nothing between them.

Silverson Conversion Tools is free to download; Pressure Vessel Heads costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Silverson Conversion Tools ships an update every 6 months, Pressure Vessel Heads every 56 months. The most recent releases landed on October 23, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | Silverson Conversion Tools | Pressure Vessel Heads |
| --- | --- | --- |
| Price | **Free** | $2.99 |
| Rating | **[4.7 (3 ratings)](https://appshunter.io/ios/app/silverson-conversion-tools/id626189811/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 6 months** | Every 56 months |
| Monetization | **Free** | Paid |
| Size | 9 MB | 1 MB |
| Requires iOS | **8.0** | 16.1 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Silverson Machines Limited](https://appshunter.io/developer/626189814) | [Imran Pinjara](https://appshunter.io/developer/1484488781) |

## What reviewers say

### Silverson Conversion Tools

[App page](https://appshunter.io/ios/app/silverson-conversion-tools/id626189811)

This app provides engineers and operations personnel with tools to calculate the volume of vertical tanks of various shapes and top/bottom styles. It also includes multiple conversion tools for common measurements and a browser for product information.

**Highlights:** Vertical tank volume calculation, Multiple tank shapes and top/bottom styles, Unit conversion tools, Email/Share calculation results, Integrated product browser

**Features:** macOS Compatibility

**In-app purchases:** none


### Pressure Vessel Heads

[App page](https://appshunter.io/ios/app/pressure-vessel-heads/id1490444646)

Calculate dimensions for various pressure vessel heads, including flat, torispherical, ellipsoidal, and hemispherical types. It provides detailed calculations for blank diameter, crown radius, knuckle radius, and height, with options for template layout marking. Input dimensions are in millimeters.

**Highlights:** Calculate blank diameter, Calculate crown radius, Calculate knuckle radius, Support for flat heads, Support for torispherical heads, Support for ellipsoidal heads, Support for hemispherical heads, Template layout marking for 2:1 ellipsoidal heads

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

**In-app purchases:** none


## Frequently asked questions

### Is Silverson Conversion Tools free?

Silverson Conversion Tools is free to download, with no in-app purchases.

### Is Pressure Vessel Heads free?

Pressure Vessel Heads costs $2.99, with no in-app purchases.

### Do Silverson Conversion Tools or Pressure Vessel Heads have ads?

Neither Silverson Conversion Tools nor Pressure Vessel Heads shows ads.

### Which is updated more often, Silverson Conversion Tools or Pressure Vessel Heads?

Silverson Conversion Tools ships an update every 6 months, and Pressure Vessel Heads every 56 months. Most recently, Silverson Conversion Tools was updated on October 23, 2026 and Pressure Vessel Heads on October 17, 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.*