tunnel filling

[jan63]

We have a 36 feet diameter tunnel supplying water to four turbines.The rated head of the units is 384 feet.Now from where the penstock of the units start the tunnel diameter has been increased.Thus we have four areas where tunnel diameter is more.On top of these four areas are air release lines used for aior release while filling the tunnel.
Now one of the air release pipes,embedded in ten feet concrete has cracked and leaks when tunnel is full.Can we plug this line.What will happen to the air at top of this area

 

[MikeHalloran]

You could plug the pipe, but then it wouldn't be doing its job. ... which may have been to protect the turbines.

Or you could line the pipe.

The technology for inserting a plastic liner into, e.g. a municipal water pipe and then expanding it, and opening any branch connections, must be pretty mature by now.



Mike Halloran
Pembroke Pines, FL, USA

 

[whammett]

I agree with Mike Halloran. Find a contractor that can insert an expandable pvc type liner. It is a quick process and depending on the contractor, you would only have to empty the resevoir for a day at most.

OR, You could plug the line, and depending on the setup, the other air release pipes may be able to compensate for the blocked one. (If I understand your setup corectly, and they are all releasing air out of the same resevoir).

"I came, I saw, I made it better."
-Ode to Industrial Engineers
Will ChevronTexaco Corp.

 

[jan63]

i am attaching drawing of tunnel.please advice after seeing it.I think air will remain trapped if we block it

 

[whammett]

Ok, simply plugging the line won't work. You are going to have to either line the pipe, or drill through the concrete to install another air release and plug the current line.

"I came, I saw, I made it better."
-Ode to Industrial Engineers
Will ChevronTexaco Corp.

 

[jan63]

thank you.I agree with the advice.At 150psi pressure plugging of line will be with risks.