Three-way control valve structure and use characteristics

Three-way control valve structure and use characteristics

April 12, 2019

3-Way control valve structure

The three-way control valve has three inlets and outlets connected to the pipeline, which is equivalent to the integration of two single-seat valves. According to the mode of action, it is divided into three-way combined flow control valve and three-way split control valve. The merging control valve is a mixture of two fluids through a valve, for example, a fluid of two different temperatures is mixed through a valve to a fluid having a temperature between the first two. This valve has two inlets and one outlet. The split control valve divides a fluid into two after passing through the valve. When the valve closes an outlet, it opens another outlet. The valve has one inlet and two outlets. Three-way split control valve Three-way combined flow control valve

3-Way control valve structure features

  • When the three-way control valve's diverting control valve is working, one passage is fully closed, and the other passage is in the fully open position. When closed, the force is similar to that of the single seat valve.
  • The three-way control valve is modified from single and double seat valves, and is guided by the valve core itself. When the gas is opened and closed, the actuator must be replaced.
  • Since the small-diameter imbalance force is small, when DN ≤ 80, the combined flow control valve can be used for the shunting occasion.
  • The three-way control valve spool is the same as the sleeve valve sleeve, and its throttle area is opened with two kinds of windows and small holes. The latter has the function of reducing noise and reducing resonance.

What is the difference between the spool position of the combined flow control valve and the split control valve in the three-way control valve?

The position of the combined flow control valve and the split control valve core are different. The spool of the combined control valve is located in the two valve seats, and the spool of the diverting valve is located outside the two valve seats, so that the spool is designed to make the spool in the flow direction In the open state, the combined flow control valve can operate stably. Therefore, in general, the combined flow control valve is used in the case of joining, and the split control valve is applied to the case of splitting.

What is the use of the three-way control valve?

  • Three-way control valves are commonly used for bypass regulation of heat exchangers and can also be used for simple ratio adjustments.
  • The bypass regulator valve regulates the bypass of the heat exchanger to control the temperature of its outlet fluid.
  • The three-way control valve is installed at the inlet of the bypass to be diverted, and the outlet installed at the bypass is merged.
  • The flow capacity of the combined flow control valve is larger than that of the split control valve, and the adjustment is expected, but attention should be paid to the influence of the temperature difference on the valve.

Three-way control valve use conditions

Usually, the three-way control valve works at normal temperature. When the three-way valve is applied to high temperature or high temperature difference, the high temperature fluid passes through, causing the tube to expand, causing the three-way valve to generate large stress and deform, causing damage and leakage at the joint. Especially in the case of high temperature differences, the impact is more serious. Generally, the temperature difference of the three-way valve is less than 150 ° C. When the temperature difference is too large, two two-way valves can be used instead of one three-way valve.

Why must the actuator be replaced when the three-way control valve is closed for air opening?

The three-way control valve is made up of a straight-through single-seat control valve and a straight-through two-seat control valve, and the valve core is self-guided, and the spool cannot be reverse mounted. When the air-closing positive-acting actuator is replaced with the air-opening, the reaction actuator must be used.