1) Floodgate 2) Head gate 3) Pipe to a waterwheel 4) Regulator 5) Sluice valve 6) Sluicegate 7) Water gate 1) Sluice 2) Sluicegate 3) Sluiceway 
A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydro turbines and sewerage systems. It is a term that has been inherited from the earlier technology of mill ponds and watermills. ==Hydroelectric systems and dams== Penstocks for hydroelectric installations are normally equippe...
• (n.) The barrel of a wooden pump. • (n.) A close conduit or pipe for conducting water, as, to a water wheel, or for emptying a pond, or for domestic uses.
A component of a hydropower plant; a pipe that delivers water to the turbine.
a pipeline bringing water under pressure to the turbine
Pen'stock noun [ Etymol. uncertain; perhaps from pen an inclosure + stock .] 1. A close conduit or pipe for conducting water, as, to a water wheel, or for emptying a pond, or for domestic uses. 2. The barrel of a wooden pump. 
A component of a hydropower plant; a pipe that delivers water to the turbine.
A closed conduit or pipe for conducting water to the powerhouse.