Steam Pipe Sizing

Need much more detailed information such as- steam source, length,layout of pipe line etc.4" is not adequate to flow 6500kg/hr at 5psi.You need 10" theoretically to flow 6500kg/hr at 15m/s.

Considering large surface area of pipe & a low pressure/ temp of steam,you are bound to have substantial amount of condensate.

In any case need more details before suggesting anything.

Ratnagiri

Hello Ratnagiri

Agree with that, but curious how you get 15 m/s for 10" pipe.

According to my data specific volume of saturated steam at 5 psig = 1.2726 m³/kg and my calc gives 45 m/s (actual velocity).

Cheers..........Codey

Codemaster,

I agree with you on the velocity it should be more than 15 m/s however I get 40 m/s.

How did you get 45 m/s?

Ciao

Dejan

Hello Dejan

I took sp. vol. as in #4 and assumed pipe actual bore = 10". Gives 45.35 m/s. If we take Sch. 40 pipe, 10.75" OD, 0.365" thick, comes to 45.17 m/s. To get 40 m/s need actual bore 10.66"

Cheers........Codey

Thanks Ratnagiri,

I agree with you and the Contractor it should be a 10" Pipe.

However is there a need for a Steam Trap Right before the Deaerator?

Ciao

Dejan

Hi dejan kindly try the link below to proper size your system and porbably find out that your contrator is right.

http://www.spiraxsarco.com/resources/steam-engineering-tutorials/steam-distribution/pipes-and-pipe-sizing.asp#head14

Ericpolc,

Very good material and reliable info.

Thanks!

Dejan

Steam pipe sizing is a professional service. You may contact us with details of PID, approx pipe isometric or layout etc

b v rao

em: purna.design@gmail.com

www.purnadesign.com

The Contractor is RIGHT.

Steam is injected at the bottom of the Feed tank cum de-aerator unit.

There will be a temperature control valve controlling the steam injection and to shut steam when desired set point is reached. The branch main bringing this steam will get water logged during shut-position and maybe a steam trap is required to drain this waterlogged branch supply main to ensure that the quality of steam is not wet. Since you have provided no drawinging therefore i guess this may be the reason for the steam trap.

Ducon,

I would love to post the drawings however they are of confidential nature.

Here is my e-mail address if you don't mind replay to it and I'll send you the drawings.

There are a few other questions I have but as you mentioned above it is difficult to analyse the questions without the drawings.

My e-mail: dejand9@yahoo.com

What is cum?

Thanks and regards.

Dejan

I would love to post the drawings however they are of confidential nature.- I understand same problem with me.

What is cum?- Combination Feed tank & Deaerator(also you will read pressure reducing cum tempertaure controlling valve). The Feed tank is mostly horizontal and the Deaerator is vertically installed on this having:

1) soft water makeup inlet point (top)

2) condensate inlet point (side)

3) Flash steam inlet point (side)from boiler blow down flash vessel(if installed) else blinded.

4) automatic air vent point (top)

5) manual air vent point (top)

6) safety valve point (top) if pressurized to get +105C feed water temperature.

7) steam inlet (bottom of feed tank) with perforated ss pipe / steam injectors inside submerged in feed water for steam injection.

8) pressure reducing valve + temperature control valve (mechanical/electrical) or like Spirax's DPT / DPE series mechanical pressure reducing cum temperature controlling valve on (7)

9) steam trap manifold to drain steam inlet pipe with drain pocket prior inlet to feed tank.

ducon,

Thank you very much for the detailed replay.

Regards,

Dejan