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My First Javascript Online Calculator – Instrument Air and Compressor Sizing

For a long time, I want to post something more advance in this blog. I always want this blog like or I want to make online calculator just like did.

Due to my limitations, at this point I cannot create online calculator. To compensate that, I tried to make useful spreadsheet.

But, today I did it! I made my first online calculator, which is instrument air sizing calculator. Please click this link to access to instrument air and air compressor online calculator. I hope you find it useful.

It is better for you to check two of previous post related with the calculator. Calculation basis used in this calculator is based on those two post.

Read Sizing of Compressor and Instrument Air Capacity

Read Spreadsheet of Air Compressor and Air Dryer Calculation


I already replaced spreadsheet attached in this post : Spreadsheet of Air Compressor and Air Dryer Calculation. So you can trace how the calculation works.


Fire Water Pump Capacity Calculation Part 1 – Fire Zones Determination

Process safety and pressure relieving and depressuring system are two areas that I want to master. Since the topic is quite big, in this post I want to share you what I learnt about fire water pump capacity calculation, specifically how to determine fire zones.

Fire water pump capacity calculation begins with fire zones determination. The whole pictures of fire water pump capacity calculation is expressed in figure below.

Fire water pump capacity calculation
Fire water pump capacity calculation

To determine fire water pump capacity, we can say we determine fire water demandMaximum fire water demand is summation of fire water required for fixed system (water spray, foam, sprinkler) and fire water required for manual fire fighting equipment (fire hydrant, fire monitor, and hose reel). (more…)

Cooling Tower Makeup Water Calculation with Example

It’s been a while since the last time I write an article about utility system. In this post I want to share you how to calculate cooling tower makeup water.

Cooling tower must be made up because the water level decrease by the time during operation. There are aspect that contribute to calculation of cooling tower makeup water. Those are:

  • Evaporation loss
  • Drift loss
  • Blow down

Total cooling water makeup water requirement = evaporation loss + drift loss + blow down.

Let’s take a look one by one how to calculate each component.

Evaporation Loss

Evaporation loss is loss of water due to evaporation. It is calculated by this equation:

Evaporation loss = 0.00085 Wc (T1-T2)


Water treatment plant balance

Water Treatment Plant Capacity Calculation

In this post, I want to share you how to calculate water treatment plant capacity. I used this term to avoid misunderstanding.

  • Raw water is untreated water coming from water source, such as from wellwater, river, or seawater
  • Utility water is raw water which has been treated and used in plant, such as for personal hygiene (flushing), utility station, cooling tower make up
  • Potable water is sufficiently high quality water which is provided for drinking, cooking, laundry, and safety shower/eye wash
  • Demineralized water is treated water which is usually used as chemical dilution of MDEA or boiler feed water

Water treatment plant capacity calculation begins with demin water demand, potable water demand, utility water demand, and the last is raw water demand. (more…)

Spreadsheet of Air Compressor and Air Dryer Calculation

In previous post, I shared about how to calculate capacity of air compressor and air dryer. In this post, I want to share you spreadsheet of the calculation. I made the spreadsheet simple so it can be used easily. You just need to input:

  • Quantity of shutdown valve (SDV)
  • Quantity of control valve (CV)
  • Number of utility station/utility connection
  • Capacity of nitrogen generator

In this spreadsheet, I assume to use dessicant type air dryer, so that you also need to input air loss during regeneration.

This is the screen shoot of example.

Air compressor and air dryer calculation spreadsheet
Air compressor and air dryer calculation spreadsheet

At the beginning, I planned to create online calculator. But I thought it will be difficult for me to prepare it and it also takes time if I prepare it by myself. I hope this spreadsheet is useful!

Compressor calculator

Download Compressor Calculator