28 inch pipe is not seen in the chart 3

[moideen]

The Bell and Gosset system sizing software indicates the pipe size as 30 inches after 24 inches. Why is there no chart for pipe sizes between 24 and 30 inches that is 28 inches (700 mm) size? Thank you

The problem with the world is that intelligent people are full of doubts, while stupid ones are full of confidence.
-Charles Bukowski-

 

[1503-44]

I did not know that the existing pipe was 28".

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

I would still just buy a 28 to 30 reducer....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Gator]

"Buy a reducer"

Yeah, not to mention availability of fittings and valves in 28", as 1503-44 mentioned.

 

[1503-44]

You will probably have to buy a 30 to 24 and trim it off at 28.
Then you could also make your 24 to 28" connections.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[MJCronin]

Once again we run down the path of solo newbie confusion !!! ...

Young newbies will never share the total problem in their first post ...Ever so slowly, you must beg for tiny bits of inforamtion ... over and over

These are the kind of resonable questions that are posed by someone who is brand new to this trade and has no one within his organization to which he can ask elementary questions... IMHO, in much of the world, there is no alternative to asking questions to strangers on the internet....

-- No company wants the burden of carrying a corporate engineering group with experienced engineers !!... No, No, No !

Every experienced mechanical piping designer and design firms know what to do regarding large-diameter piping retrofits and the shop modification of piping reducers... this fabrication issue has been addressed so many, many times before !

We are now ready for your next question, sir ...

MJCronin
Sr. Process Engineer

 

[moideen]

@LittleInch,@Gator,@1503-44,@MJCronin
Perhaps my language is insufficient to persuade the subject in question. I apologise. The subject at hand is not just how to connect 28-inch pipe to 30-inch pipe. This project's new consultant is distinct from the previous consultant who were the principal designers of the complete plant. The new consultant advice to replace all including headers!!!Please keep in mind that the consultant proposes replacing the current full-length 28-inch pipe. That is, from the ground floor to the 3rd floor basement where the CHW plant (21,000 TON) is laid out! They recommend replacing the complete 42-inch (1000-mm) header! Leave the header issue alone and concentrate on the 28-pipe work, whether required by engineering, the ASHRE code, or an industry standard. Do you agree, even without knowing the technical justification?

The problem with the world is that intelligent people are full of doubts, while stupid ones are full of confidence.
-Charles Bukowski-

 

[1503-44]

Systems composed of mostly imaginary parts hardly ever work.
Do the availability study; that was your initial question in a way; then make your decision.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[georgeverghese]

I dont see why this program should not permit the rating check of 28inch pipe. It is non standard, but a cautionary footnote should have sufficed. A pipe mill can supply you non standard dia pipe if you order sufficient length to justify the production. Otherwise, there should be an option to manually input a given pipe id in this program.

 

[IRstuff]

It's free software from the manufacturer of pipes, so I would think that their primary interest is in sizing problems with their piping products as the solution

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[moideen]

The McQuay design tool operates correctly and has access to all variables. This guarantees that the velocity and friction loss are both kept within the proper limits of the current design. According to ASHRAE, HVAC system velocities between 10 and 17 ft/s do not result in pipe erosion or noise.
18,000 US gpm with 28 inches of pipe
Schedule 40
Velocity: 9.9ft/s(3 m/s)
Friction loss: 0.83ft/100ft
hydraulic radius of 6.4 inches

The problem with the world is that intelligent people are full of doubts, while stupid ones are full of confidence.
-Charles Bukowski-