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Why do we need to make complete technical bid tabulation, requisition, or data sheet?

Rifka Aisyah Leave a comment

Now I undestand. People said experience is the best teacher. I think that’s true.

I have already follow procurement of several equipment package since the beginning. I compared my preparation and others (especially preparation of engineers from our head company). My preparation was way way incomplete. I felt the effect right now.

One of my colleague asked me if the internal of pressure vessel in water treatment plant will be spark tested or not. The purpose of spark testing is to determine if there are leaks in the rubber lining and identify the locations. It is a mandatory test in rubber lining tanks.

So, what is the problem? The problem is, for any reason, the appointed vendor cannot perform the test. They just give us the guarantee that there will be no leaks in the lining.

I have googled and found that some vendors perform pre- and post-cure inspection for rubber linings. I got to understand that the test was very important.

Back to the topic. I wish I could turn back time and wrote on my technical bid tabulation and requisition, and data sheet about the point. I did not have spend time to focus in such details. That’s something which is not our concern at the beginning and at the last it became a problem.

Lesson learnt: be detail in making technical bid tabulation. Consider many factors. Ask your colleague or somone who has more experience than you. 

Where to install pressure gauge at pump discharge line

Rifka Aisyah Leave a comment

Yesterday I had enough time to increase my basic knowledge in chemical engineering because I had finished my works. Then, I stumbled upon this link and started to think about my piping and instrumentation diagram. I realized I had make a fundamental mistakes. I felt useless.

I am writing this post so that I will remember my mistakes and never try to do it again. Hope you find it useful.

Remember everyone! Pressure gauge shall be installed after pump discharge nozzle and before check valve. The consequence is if you have two pumps (one is running and another is stand by, then you have to install two pressure gauge). The reason is:

  • To show actual pump discharge pressure. If you install pressure gauge after check valve, the value of discharge pressure won’t be actual due to pressure loss of check valve
  • In the case of check valve failure, pressure gauge will show actual discharge pressure. If the pump has problem, pressure gauge will show pressure value lower than usual

Discussing about Fire Extinguisher with Vendors

Rifka Aisyah Leave a comment

Yesterday I got a quite tough and long discussion with one of fire extinguisher product vendor. I learned that I need to define what I really want, what scope of supply is, and what scope of works is. The discussion became very unefficient at the beginning because of those issues. My action was late so that I could not control the discussion. Fortunately, it was clear at the end.

I have created material take off for fire extinguisher and other related products, such as hose reel, potable fire extinguisher, manual alarm pull station, smoke detector, hydrant pillar, hydrant box, siamese connection, and water spray for the tanks. However, there were several issues that has not been addressed. Honestly, the discussion broadened my knowledge because the vendor has a lot of experience (I think). In this post, I want to share to you some of the points. Read More

Pump Inspection and Factory Acceptance Test

Rifka Aisyah Leave a comment

The opportunity to witness Factory Acceptance Test (FAT) of pumps came to me. About a week ago I visited our vendor’s factory at Industrial zone in Pulogadung, Indonesia. Our plan was to witness the performance of three different pumps.

www.torishimaguna.com

Our pumps were not API pumps therefore the performance test procedure was quite simple and quick. The performance test of one pump took less than 30 minutes. However, the preparation, such as mobilization of pump, installation, make sure there’s no leak in the pipe, took longer time than the test itself.

There are several parameters to be checked during test, suction head, discharge head, rpm, power, voltage, bearing temperature, vibration level, and noise level. The pumps were operated under different flow rate, such as 0%, 25%, 50%, 100%, and 120% capacity, and at minimum flow. Those parameters were checked at different flow condition.

After we got the actual parameters, we plotted on the graphs. Then we compare the actual performance with design performance. The deviation shall not more than 6%.

 

Water Chiller Inspection: My First Experience

Rifka Aisyah Leave a comment

Today, the project manager our EPC project asked me to participate in water chiller inspection in Cileungsi, Bogor, Indonesia. It was my first time. So, I felt a bit excited as well as confused. On that inspection, my role was to inspect the equipment and the technical aspects. I actually did not have any idea about the equipment, except the function.

Simply, we can say water chiller is a refrigeration device. It is used to cool a process fluid. A chiller will use either a vapor compression or absorption cycle to cool.

Type of Industrial Chiller

Figure blow shows type of industrial chiller.

 

Component of Chiller

The basic component of chiller are compressor, evaporator, condenser, and thermostatic expansion valve.

Wastewater Treatment System

Rifka Aisyah 1 Comment

A few weeks ago I got a discussion about wastewater treatment system in our proposed plant. I discussed with one of my colleague. He said, “Let the nature works! Let it process the wastewater by itself”. It sounds weird at the first time. But he’s right and he’s a bit wrong.

He’s right because the natural water in streams, rivers, lakes, and reservoir have a natural waste assimilative capacity to remove solids, organic matter, even toxic chemicals in wastewater. He’s a bit wrong because the process takes a really long time. That’s why we need wastewater treatment system to make it quick (read more in Water and Wastewater Calculation Manual). Read More

Hydrostatic Test for Boiler

Rifka Aisyah Leave a comment

I just got an opportunity to witness hydrostatic test for boilers in my recent EPC project. Hydrostatic test is the most common procedure used to qualify newly manufactured pressure pressure. The purpose is to make sure here is no leak in the boiler.

The procedure was quite simple yet important. Pressure parts shall be subjected to a hydrostatic test pressure which at every point is at least equal to:

1.5 times the MAWP (Maximum Allowable Working Pressure) for ASME section I code.

1.3 times the MAWP for ASME section VIII Div. I code

(The MAWP may be assumed to be the same as the design pressure)

The design pressure of my boilers is 10 barg. When this test applied, the QC engineer increased the pressure of boiler to 10 barg and hold it for 15 minutes. They checked visually the internal of boiler if there’s a leak. Unfortunately, there’s no digital recorder available to record the pressure of boiler during the test. So, we needed to check by our naked eyes the pressure gauge.

After 15 minutes, the increased the pressure to 15 barg at hold it for an hour. After that, they decreased the pressure to 10 barg again, hold it for 15 minutes, then decreased again to 1 barg. The inspection was done visually.

Assessment of Cooling Tower Performance

Rifka Aisyah 3 Comments

Yesterday, I just got an opportunity to inspect some of cooling tower equipment, such as motors, fans, fan stack, low oil level switch, and so on. It was great. I got more understanding about the system, which is very valuable for me as young chemical engineer.

Before I do the inspection, I tried to learn something about cooling tower. I found from this link about how to assess a cooling tower. In this post I want to give you an example of my own cooling tower.

There are several parameters to assess the performance of cooling towers. Note: CT = cooling tower; CW = cooling water Read More

Heat Loss Calculation of Tank Heater

Rifka Aisyah Leave a comment

My recent study was to calculate heat loss in tank heater in order to determine condensate load. It was a pretty simple method. In this post, I provide you the example of my calculation and I hope you find it useful. The problem statement was:

  1. Heat marine fuel oil from 50 to 60 degree C in 5 hours
  2.  Continue to maintain 60 degree C in an insulated tank with a wind velocity 10.08 km/h and an ambient temperature of 27.4 degree C
  3. Tank is 6.8 m diameter and 6.04 m of height
  4. Steam is available at 8 barg

You can find the source of my calculation from this link.

Calculation of tank heater heat loss.