steam trap selection

[ram21881]

I have a technical specification for steam trap type thermodynamic with material body A105, material of seat and cone S.S but it’s mentioned that the material of the thermal control element is S.S.
I am a new at the field of buying steam trap but my understand that is thermodynamic type disc which is mentioned for it the specification but thermal control element make me confused is it thermostatic type , like Flowserve Gestra BK45 OR what ?
For vertical installation, capacity 200kg/hr- diff pressure 2.7-3 bar- operating temperature 160c.
Is that the suitable trap Flowserve Gestra BK45 for these requirements?
Appreciate the help

 

[TD2K]

If they have specified a thermodynamic type trap, I would think the comment " thermal control element is S.S" refers to the disk.

 

[EmmanuelTop]

According to the manufacturer catalog, capacity of Gestra BK45 is sufficient to meet your specified flow.

Without knowing other details it is hard to say whether this particular model is the right fit. Perhaps you can find out more at:

http://www2.spiraxsarco.com/resources/steam-engineering-tutorials/steam-traps-and-steam-trapping.asp

http://www2.spiraxsarco.com/resourc...-steam-trapping/thermodynamic-steam-traps.asp

http://www2.spiraxsarco.com/resourc.../considerations-for-selecting-steam-traps.asp

Dejan IVANOVIC
Process Engineer, MSChE

 

[ram21881]

thanks alot TD2K & Emmanueltop,
burt what do you think regarding the attached types the best one to select for this case , if it compare with the Gestra BK45.

 

[georgeverghese]

A TD trap works by enabling condensate that is subcooled upstream of the trap - you havent said whether a cooling leg is installed upstream of this trap and whether it enables this 10degC subcooling in this cooling leg at the required design flow of 200kg/hr. All we know now is that the "operating temp" is 160degC.

 

[ram21881]

it's for low pressure steam condensate headers for steam tracing to keep the process line heated Δ p max / Δ p min = 4.5/2.5 bar , operating pressure 3.5/5.5 bar , max alawable working pressure -1 / 9 bar.

 

[georgeverghese]

So at the min operating 3.5barg sat steam, we have Tsat=147degC, so the thermal design of the cooling leg should show that the 200kg/hr of condensate has cooled down to less than 137degC by the time it reaches the TD trap. And this temp drop of 10degC should happen with natural convection at zero windspeed and max external ambient temp. Ask a process engineer to help you out with this. Also account for the low internal htc of the condensate ( probably natural convection current controlled also).

 

[TD2K]

THe two traps look fairly similar in performance if I look at a 3 bar differential. They aren't exactly the same but they are in the same ballpark. Do both meet the system's design P and T requirement?

The main difference is that the Genstra is a thermostatic trap and the Velan is a thermodynamic trap. Both look like they will discharge condensate at close to saturation temperature.

It really comes down to the site's preference for steam traps and their operating experience in terms of reliability.

 

[georgeverghese]

Pressure downstream of the trap of 1.0barg sounds somewhat low - may need to be checked again.