Steam pipe sizing in easy 5 stages

Steam pipe sizing

Steam Piping sizing is very important for chemical engineer or mechanical engineer or Piping design engineer.

As we know that steam is very important in almost all kinds of industries like the sugar manufacturing industry, pharmaceutical industry, chemical industry, oil and gas industry, paint and dyn industry.

In today’s article we learn some basic information about steam like, how to produce steam, what is steam , application of steam and steam pipe sizing or steam line sizing calculation.

What is steam ?

Steam is nothing but the vapor phase of water. When we heat the water to its boiling point steam will start to form. Steam temperature varies with steam pressure. Steam comes under compressible fluid category.

How steam is generated ?

There are different equipment available for steam generation. Mostly or largely used equipment is nothing but a steam boiler. Steam boilers are commonly used in all types of industry like to produce steam. There are different types of boiler available to produce or general the steam, steam pipe sizing calculator excel.

There are two types of boiler as per it’s boiling mechanism.
1) Tube fire boiler
2) coil fired Boiler

Appart from above types boiler further classification is as ,

1. IBR Grad boiler
2. Non IBR Grad boiler

Steam Piping sizing calculation

There are two types of methods available for the calculation of steam line sizing.
1) Using the velocity
2) Calculating the velocity

In pipe line sizing calculation method it is very important to know the information about velocity consideration. Velocity plays a vital role in piping design for steam. Not only steam but for the sizing of water pipe, gas pipe or any liquid pipe, velocity consideration is very very important.

You can read our article on line sizing calculation which gives you basic information about piping design.

We use following formula for steam pipe calculation,

flow rate = velocity * cross sectional area

In SI units ,

We take flow rate in M3/sec,
Velocity in m / sec,
And area in meter,

We can simplify the above equation as,

Q = v X A

So to calculate v formula become,

V = Q / A

I .e velocity necessary for steam flow “Q” through cross sectional area A is Q /A.

Again vin terms of direct diameter calculation required for the flow of steam is,

D =√Q / (0.785 * v )

Where D is required diameter for steam pipe sizing calculation,
And v is velocity in m/sec.

0.785 is the value of π/4.

Cross section area formula is,

Area = π/4 X D^2 ,
Where D is the diameter of pipe.

So there are two methods by which we can do the steam pipe sizing calculations.

In the first method of steam Pipe sizing calculation we directly consider the velocity as per thumb rules or standard available. Using velocity we directly calculate the diameter by following formula for steam pipe size calculation,

D =√Q / (0.785 * v )

Note – please make sure the correct use of unit of measurement. Correct unit of measurement is very important to get write answer.

In second method we calculate the velocity using following formula,

V = Q / A
Where A is , π/4 X Diameter.

In the second method of steam Pipe sizing calculation we assume the diameter and calculate the velocity. If velocity matches the thumb rule or standard then our assumption of diameter is correct. If not matched then we need to change the diameter of the pipe and need to do hydraulic calculation again.

Velocity for steam pipe sizing calculations

As we know that steam is strongly related with pressure. If we increase the pressure of steam the steam temperature also increases. For high steam pressure we need use high velocity. In industry steam can classified as Low pressure steam , mid pressure steam and high pressure steam.so in steam pipe sizing calculations we need consider,

For low pressure steam ( up to 4 bar) use 15 to 25 m / sec velocity,

For mid pressure steam (4 to 8 bar ) use 25 to 35 m /sec steam velocity.

For high steam pressure ( 8 to 10 bar )use 35 to 40 m/sec velocity.

How ever pressure range will vary organisation to organisation , in some organisation standard they consider only low pressure steam and high pressure steam only.

following is example of steam Pipe sizing calculation.

Example no 1

Calculate the pipe sizing required for 0.5 M3/hr steam of pressure 3 bar.

Calculation ,

We can solve the above equation by our two methods as discussed above in article.

Note – In this article we consider steam flow directly as m3/hr i.e. we consider volumetric flow directly but in general we need to design the steam pipe with mass flow rate as 100 kg/ he. So you need to convert the mass flow rate in to the volumetric flow rate using steam table or steam density.

We solve the above example with considering velocity as per standard directly,
So let us consider the velocity, 20 m / sec, as this low pressure steam of pressure 3 bar.

So diameter calculation become,

First we need to convert the flow into M3 / sec from M3 / hr , because use unit of velocity in m/sec.

So Q become, 0.5 / 3600 = 0.0001388 M3 / sec,

My sincere request to all of you, please solve and comment the answer below, I will check it.

Conclusion

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Hydraulic calculation

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steam Pipe sizing calculator