In this post I want to share to you how to do preliminary sizing and horse power estimation for counterflow induced-draft cooling tower. Calculation in this post do not apply to counterflow cooling tower. Also they do not apply when the approach to cold water temperature is less than 5oF (2.8oC). Read More
Category: Utility System
Cooling Pond Sizing
In this post, I want to share to you how to size cooling pond. Cooling pond is used to remove heat from water by means of air. Example of application of cooling pond is to remove heat from brine water in geothermal power plant facilities.
To design cooling pond, you need process data and environment data. Process data are flow rate of liquid to be cooled, initial temperature, final temperature, and density of liquid. Environent data are relative humidity, wind velocity, average air temperature, and solar heat gain. Here is example of cooling pond sizing. Read More
Pneumatic Power Supply for Instrumentation and Its Selection
In almost every plant, we need to install control valve, shutdown valve, and/or blow down valve. These valves can be operated by power supplies from pneumatic system, hydraulic system, or electrical system. In this post, I want to share you pneumatic power supply for instrumentation and general guidelines for selection. Read More
Visiting Drinking Water Treatment Plant in Tirtawening
On December 2017, I got an opportunity to visit drinking water treatment plant in Tirtawening, Bandung, which is near my college. It was a very amazing experience, because this is my first experience visiting water treatment plant. And also, experience like this is very rare after I entered working environment.
This site visit is actually a part of water treatment plant training. I will share you about this training in different post.
Drinking water treatment facility in Tirtawening is actually the biggest one in Indonesia. It processed 2000 liter/second water, from two trains (rate of each trains is 1000 liter/second). 1900 liter/second water is sent to customers and 100 liter/second water is own used. Read More
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 engineeringtoolbox.com or checalc.com. I want to make online calculator just like checalc.com 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
BONUS!
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.

To determine fire water pump capacity, we can say we determine fire water demand. Maximum 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). Read 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 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. Read 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.

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!
Nitrogen Gas Supply System
It is quite some time I don’t write about utility system. In this post I want to share you some basic knowledge of nitrogen supply system. In December 2015, I prepared several training presentation about nitrogen supply system when I was working in this company. I think it is a good idea to share some of them.
Nitrogen is used for purging activity and blanketing due to its unreacted feature.
Nitrogen is used at different application, depend on its application.
Required nitrogen purity based on its application
