Boiler Feedwater Pipe Maximum Flow

What do you think it is? Do you have any figures?

In my entire span of engineering , this is the 1st time I heard about a process boiler that BIG. Maximum i came across was 25 Tph/10 bar x 2. Garioni & standardkellel makes 50 tph/1o bar firetube. What make is this boiler? and what process do you have?

Again, you should ask the manufacturer because they have supplied you the feed pumps x 2 sets coupled with the boiler.

( To me it seems ok to pass 168 TPH at recommended minimum velocity of 1.5 m/s with pressure 1~10 bar.A 6 in pipe would have been ok too.)

At the velocity of 6 ft/s, an 8" pipe delivers about 940 gpm ≈ 231 TPH flow, and you could go even higher. So the pipe is not likely to be the limiting factor; it might instead be pumps or valves.

Boiler's as operated in battery but with leakage in 01 HP heater, the flow of 02 boilers is diveretd through single HP Heater. Boiler FW pressure 140kg/cm2 and 115TPF. FW line is of 8inch. Please suggest how to calculate or only practically it can be seen?

Today I operated it on 175TPH

Tornado and myself confirmed on your line size which was your initial question.

You havent't answered mine.

the flow of 02 boilers is diveretd through single HP Heater. = you mean HP Header?

your are confusing also. When you say you operated it at 175 tph with a boiler initially stated 115 TPH WHAT THEN IS YOUR PROBLEM!!!!!

Remember to adjust for friction loss per 100 feet. Worse for old pipes and high flow rates. Is that really 2000 PSI in the 8 inch pipe?

115 TPH at 140kg/cm2 and 140degree temperature.

You mean 140 psi NOT kg/cm2 then the temperature 140 degrees C do not meet!!!!

Let me clear all your Doubts.

Feed water temperature 140degree, pressure 140kg/cm2, 8 inch pipeline

Boiler capacity 115TPH, 90kG/CM2 and 535degree.

02 separate feed water lines with 01 common header for 02 boilers running in battery.

Can I run Both boiler on full load (115*2TPH) with common header in line and 01 FW line in isolated condition?

Is the matter clear?

I will cite our experience with our own system. Hope that may clarify.

In our case, We have two boilers having individual BFP's of 250TPH,110Kg/cm2, 160deg capacity. BFP Discharge headers of both the boilers are connected with a Common Header of nearly same diameter that of individual discharge headers. But when BFP's of one boiler is not in service, We can't run that boiler at full capacity [ Infact we can run that boiler at 50 % or less load] since the running BFP of the second boiler will trip at "Discharge Pr Low".

So that could mean that 1) We can try with one line only when the running BFP is at much higher pressure [ which will increase the velocity & hence flow]

& 2) When a pipe line is designed [ with particular dia & thickness], At some point of tonnage flow , the wall thickness of the pipeline will come as a restraint. In this, dia will not be restraint, since our 68ata header [carrying 2 to 3 boilers of 200TPH capacity] is of only slighter bigger diameter , but its wall thickness is higher.

Kindly reply whether you concur with the idea or not

Dear Mr.brijesh jp,

The Common Header size should be of higher size equivalent to 2,5 to 3 times of the total flow area of the individual pipe. same size will offer constricted flow.

DHAYANANDHAN.S