Operating positions for two-port valves might be either shut (closed) to ensure that no flow in any way goes thru, fully open for max flow, or sometimes partially ready to accept any degree among.

Operating positions for 2-port valves might be either shut (closed) to ensure that no flow whatsoever undergoes, fully open for max flow, or sometimes partially available to any degree among.

On/off control -- stopping and restarting system fluid flow -- is the most basic valve function. Primary on/off options are ball, gate, diaphragm and bellows valves.

I installed a ball valve a couple weeks ago to work as an iodine fillup on a dairy farm.

Of all the various types of valves available on the market for liquids, ball valves are probably the most common.

A non-return valve is a globe valve with the disk attached so it can slide up and down. Back pressure will shut the valve even if the handwheel is in the open position.

Rain collected from the roofs of farm buildings can be re-used for a variety of activities, including washing down yards.

Those ball valves are not stainless, but plated brass.I bought the exact same valves.