Hydraulic components commutation adjust the throttle and throttle check valve flow control valve is a simple, quantitative pump hydraulic system, with the throttle valve and pressure relief valve, can compose three throttle control system, that is, into the oil Road throttle control system, speed control system and return oil throttle bypass throttle speed control system. No negative feedback flow throttle function, can not be compensated by the speed load changes caused by instability, generally used only for little change in load or speed stability less demanding situations.
Performance requirements
On throttle performance requirements are:
- Flow adjustment range, smooth flow of a pressure changes;
- Small internal leakage, if leakage leakage port, external leakage also small;
- Adjusting torque, quick action.
Hydraulic components commutation adjust the throttle (Choke valve) is no different form factor and cut-off valve, but the shape of their opening and closing parts are different. Throttle opening and closing pieces streamline conical mostly through which the cross-sectional area and change the channel to regulate flow and pressure. Throttle valve for the pressure drop under conditions greatly reduce the pressure of the medium used.
Media between the throttle valve and seat velocity is large, to cause these parts of the surface quickly damage - the so-called cavitation. To minimize cavitation effects valve resistant to cavitation material (steel manufacturing) and made into the top corner 140-180 streamlined cone, which also enables the valve to have a larger opening height is generally not recommended throttling at small gap.
Feature
1, the structure is relatively simple, easy to manufacture and maintenance, and low cost. 2, regulation accuracy is not high, it can not be adjusted to use.
3, the sealing surface erosion prone, can not be cut off by the media.
4, poor sealing.
Classification of hydraulic components commutation adjust the throttle by the channel can be divided into straight and angle type two; according to the shape and closing parts of the points, there are needle-shaped, groove-shaped and window-shaped three.
Adjustable throttle valve: a valve needle and spool using carbide manufacturing products according to API6A standard design, with wear and erosion resistance performance. Mainly used for wellhead oil (gas) tree equipment,
Slip-hydraulic components to adjust the throttle change: spool with low noise balanced structure, open lightweight products according API6A standard design, the valve cover tungsten carbide surface adapted to have a flash, high differential pressure and high pressure air and other harsh conditions of the occasion, long life, flow control accuracy is improved greatly. It applies to oil, gas, chemical, oil refining, utilities and other industries.
Applications Due to throttle the flow rate depends not only on the size of the orifice area, but also with the differential pressure orifice before and after the related valve stiffness is small, it is only applicable to the actuator load change is small and the speed stability less demanding occasions.
Big Changes for the actuator load and high speed stability requirements throttle control system, the throttle pressure compensation must be maintained before and after the throttle pressure constant, so as to achieve stable flow.
