http://en.wikipedia.org/wiki/Penstock U can get the answer from the above link
penstock
The giant tube in a hydropower plant is called Penstock. A Penstock is refers to the enclosed pipe that delivers water to the hydro turbines.
Pressure Shaft is designed to resist Internal as well as External Pressure, but the Penstock is designed to resist Internal Pressure only. - Saravanan.S
its connected at the start of penstock to reduce the "water hammering effect" in it.
ONLY 1 PENSTOCK that's all
Head race tunnel are Non pressurized tunnels and Penstock is the tunnel bearing pressure. As there is the breakdown in the Power and the water is stopped entering through the turbines, the pressurized flow of water in the penstock creates hammer effect and goes back to the HRT. So, keeping Fore bay in between HRT and Penstock helps reducing pressurized water to create Water Hammers. Hence, to reduce the back water pressure effect, the Fore bay is used in the Hydro power Plant.
How much does it cost monthly How much does internet service cost in the Orlando area? How much does it cost?
How much did the mausoleum at Halicarnassus cost?
about 2.00$
Pen stock is made of pipe while Tunnel is not a pipe.Tunnel is made of concrete material.
how much does 1 heaping teaspoon of baking powder cost