The Three-Way Valve junction type always connects to three pipes. This junction type allows you to model the irrecoverable losses that occur through a valve with multiple inlets or outlets.

The Three-Way Valve Properties Window does not follow either of the two basic Properties Window formats, but instead shows the connecting pipes in drop-down lists. This allows specification of which pipe is the combined flow pipe and which two are the split flow pipes.

All losses in a Three-Way Valve are based on C_v (or K_v). The C_v data is entered for various percent open positions, and the user ultimately specifies the actual percent open to be used in the model. The resulting C_v values for the two flow directions are calculated and displayed. A graph of the open percentage, C_v, and flow area data can be displayed by clicking the Show Graph... button located below the Open Percentage Data table.

Special Conditions

When the specified percent open value input into the Actual Percent Open box corresponds to a C_v of one or both flow directions to be zero, a Special Condition is applied to the corresponding flow direction(s), causing the valve to close in any direction in which the C_v is zero.

Transient

(XTS Module Only) On the Transient tab, a transient open percent can be entered to simulate the position changes of the valve over time. For more information on transient data, including event transients, see Junction Transient Data.