Four way three position valve (TL)#

Four way three position valve (TL) models a valve with four orifices in a thermal-hydraulic network, typically between an actuator, pump, and tank. The valve is controlled by a single spool, the position of which is determined by the signal at port S. The block has two inlets — P and T and two outlets — A and B.

The block consists of four hydraulic orifices paired—PA, PB, TA, and TB. See the mathematical model in the block Hydraulic Orifice (TH).

The flow area of the orifice depends linearly on the spool position and is described by the formula (1):

(1)#\[A_{orifice}=\frac{A_{max}-A_{leak}}{\Delta S}\cdot (S-S_{min})\cdot \epsilon + A_{leak}\]

where:

\(S_{min}\) - parameter Spool min position, [m];

\(\Delta S\) - parameter Spool stroke, [m];

\(A_{max}\) - parameter Maximum area, [m\(^2\)];

\(A_{leak}\) - parameter Leakage area, [m\(^2\)];

\(\epsilon\) - parameter Opening Orientation.

Hole_pattern — Orifice operation diagram depending on the spool position.#

1. Properties#

Property	Default Value	Description	Units of measurement
Area port	0.001	-	m\(^2\)
Maximum area	1.0e-4	-	m\(^2\)
Leakage area	1.0e-9	-	m\(^2\)
Spool min position	0.01	-	m
Spool stroke	0.05	-	m
Discharge coefficient	0.64	-	-
Critical Reynolds number	150.0	The Reynolds number at which the transition from laminar to turbulent flow occurs	-
Smoothing factor	0.01	-	-

2. Inputs and outputs#

Parameters	Input/Output	Description	Units of measurement	Port type
Spool displacement	Input	-	m	Automation
Port P	Input	-	-	Thermohydraulics
Port T	Input	-	-	Thermohydraulics
Port A	Output	-	-	Thermohydraulics
Port B	Output	-	-	Thermohydraulics

In order to see the connection capabilities of the block, you need to go to page Description of block ports