Utility Piping | Steam Piping - Steam Heating

In Previous Article We seen the different use and types of steam.

We know the dry saturated steam is generally used in pipe heating process.

Steam is one of the most common and effective heat transfer mediums used in industry, but it is not the only medium available. Other fluids such as hot water and oil are also used for indirect heating in heat exchangers.

So following are the advantages of steam heating:

In case of heating with hot water it only loose sensible heat around 17kcal/hr But if we use dry saturated steam then it loose latent heat around 539kcal/hr.

So we can see the use of the steam is more preferable in case of pipe heating.

There are different way of heating:

Mainly steam tracing and Pipe jacketing are use:

1. Steam Tracing:

As shown in figure in a steam tracing tracer pipe is bounded around the base pipe.
There are number of tracer are used according to the requirement.
Size of the tracer are varied from 1/2 inch to 1 inch. 
Copper is costly so carbon steel used.
Expansion loop in the tracer is provided at every 30 meter.
Tracer are generally locket at bellow of the pipe.

2. Jacketed Heating:

It is mostly use for heating purpose.

There are Two Types of jacketing:
Partial Jacket and Fully Jacket.

Spacer are used at regular interval to maintain distance between pipe and jacket.

In a full jacketing all the pipe element to be jacketed like elbow and tee, flange...etc.


In case of individual jacketing it is not long more than 6m due to thermal expansion.
Jumper is used in case of partial jacketing for transfer of steam.

There are various problem occur in case of steam heating...

1.Temperature problem caused by Air:

Is the supply steam to your process at the correct pressure, but for some reason under-temperature? Does the product fail to heat up to the correct temperature? Air can diffuse and mix with steam at start-up or during regular operation, which effectively reduces the steam pressure and results in reduced heat transfer. This phenomenon can be explained by Dalton's Law of Partial Pressures.
Also there are various gases are desolved in water at atm pressure but when pressure reduse it start evaporate and make air pocket in piping.

So as we know air is not a good conductor of the heat transfer as steam so it is required to remove air from pipe.

There are different types of air-vent used for air remove.

During starting of any plant it is required to remove air first so air vent should provided with steam trap.

2.Second major problem in steam heating is condensate removal:

To remove Condensate at regular interval  steam trap is used.

So steam trap is a type of automatic valve that filters out condensate (i.e. condensed steam) and non-condensible gases such as air without letting steam escape. 

Following are the different types of steam trap

Thermodynamic steam trap: It operate base on the density different between condensate ad steam.

Thermostatic Steam Trap: It is same as Thermodynamic steam trap but in this expansion bellow use.

Inverted Bucket: This type of steam trap used in main steam line to remove large amount of condensate.

Float Ball steam trap: It is steam trap in which ball valve used to control the condensate removal.  

Steam trap should install at every 30 to 60 m in straight pipe.

If there is bend then install before bend.