prosthetic arm on blue background

Reboot Engineering….

Post 1 of many 🙂

Idea in WIP

Something I wanted to do for long, building something by my hand! Building machine from scratch.

End of mansoon brought some ideas and inspiration, which I thought will lead me to fulfilling my etch of doing some engineering. Yes, I’m full time engineer, but now a days expertise lies in mentoring engineer and inspiring them with new ideas. The skill of doing a project like this one from scratch was long un touched. And I think its time to sharpen that axe.

Let me keep posting here, my journey toward completing this small project, and capturing learnings on the way. Follow along this story with tag #reboot

Heat exchanges… Google way.

If you Google the word you will get morecthan a billion results. That just shows how it closely associated to industry, to us.

But at the same time ut shows how wast  the subject is.

The purpose of next few blows is to simplify your search by telling you what to ask and where to see.

Figures crossed 🙂


Past few months I was thinking of creating a post on heatexchangers. I think now is the time when i can write a bit on this subject.  

There are numerous sites available which will explain verwell about this subject. But as usual they lack the subject matter. What we all are interested in. The core, the ‘how’s part of it.  

In my next few pposts you fand this information.

Take care.

Heads as per ASME : Quick overview

I was studing some heads for a while, and thougth to summarise the variety in one go…

1.      Flanged Head : Normally found in Vessel opertaing at low pressure, genrally water tanks, Boilers etc. They are also used in high pressure application where the diameter is small.
2.      Hemispherical Head : Generally, the required thickness of the hemispherical head due to a given Pressure & temperature is half of cylindrical shell with equivalent diameter & Material.
3.      Elliptical and Torispherical (ASME Flangged & Dished) heads : they are very popular in pressure vessel, their thickness is ususally same as the cylinder to which they are attached.

This is a quick heads up for variety of heads used in industry. The other type are
1.      Conical or Toriconical head: they mostly form bottom end closure for the vessels, and act as hopper, or to give easy drainability. The important thing to consider while designing this heads are, a) they increase the overall height of the vessel. b) ASME need to do discontinuity analysis for half angle >30 deg, or else one need to go ahead with toriconical head to avoid the unbalanced force at the junction.
2.      Miscellaneous head: Many chemical process requires unusual vessel configuration, the heads of such vessel can have unlimited configurations. The design of such head is very complicated, and there is no straight forward formula for that.

Keep reading!

Process Piping Pressure Calculation : B31-3

B 31.3 is an ASME code for Process piping, Multiple time we come across situation, where we need to calculate the design pressure for a pipe.


In such cases, ASME VIII-Div-1 seems helpless, and B 31-3 comes for rescue.


Clause 304.1.2 talks about Straight pipe under internal pressure,




P > Internal design pressure

D > Outside diameter of pipe

S > Stress value of material as per table A-1

E > Quality factor from Table A-1A & -1B

Y > Coefficient from table 304.1.1


Compare equation 3a with ASME VIII-1 Formula (UG-27)

The formula is completely same, except factor PY against 0.6 P!

Y factor varies from material & Temperature, which varies from 0.4 to 0.7


As I’m working on one of the project, where I’m manually doing calculation, I thought this will be fastest way to share!


Keep reading!


Code Comparison : Discussion:1

Scope & Responsibility:

Let’s start with comparing the scope & Responsibilities for various codes.

Following table will give an overview



EN 13445



Ref ASME VIII-1 U-1   

Pressure Not exceeding 20 MPa U-1(d)

Design by Formula

Minimum pressure 15 psi (g) [1 bar(g)]  

Minimum -ve pressure 15 psi (g) [1bar(g)]                                              

Refer EN 13445-1: 2009

No limit on pressure

Design by Formula & Design by Analysis

Minimum pressure 0.5 bar(g)

Minimum -ve pressure -0.5 bar(g)

Refer GB-150 : 1-1.1

Pressure not exceeding 35 MPa

Design by Formula

Minimum pressure 1 bar(g)

Minimum -ve pressure 0.2 bar(g)


Ref VIII-1 U-2 (b), UG-90

Responsibility of Manufacturer to design complete

vessel as per requirements of Code

19 responsibilities with Manufacturer, 14 with AI

Refer EN 13445-1: 2009

Responsibility of Manufacturer, counter signed by

notified body (Independent agency)

Annex – H to be filled & Signed

GB-150 : 3, Clause 3.2.2

Responsibility of Manufacturer & Designer to design

complete vessel as per requirements of Code

Next Topic Material & Properties!

Keep Watching!


Code Comparison : A Startup

With my next feeds, I’ll be comparing following Code on various aspects


European Code :          EN 13445

American Code :          ASME Section VIII Div. 1

German Code:             AD : 2000

Chinese Code:             GB: 150


Keep watching!