There are a number of manufacturing methods used for the manufacture of control valve trim components, some of which are expensive processes. Current market conditions and increased competition requires manufacturers to reduce costs of these components and they are investigating new technologies such as processes using Additive Layer Manufacturing (ALM) to produce these components. These proces...

Abstract. This work presents a cascade controller for the trajectory tracking control of a hydraulic actuator by using adaptive algorithms to deal with parametric uncertainties together with an adaptive dead-zone compensation scheme. The hydraulic actuator is modeled as a forth order nonlinear system including the valve dynamic as a first order linear system and considering a valve with a dead-...

Hydraulic systems, as power sources and transmissions, offer many advantages over electromechanical or purely mechanical counterparts in terms of power density, flexibility, and portability. Many hydraulic systems require touching and contacting the physical environments; and many of these systems are directly controlled by humans. If hydraulic systems are passive, they would be both safer to i...

In this paper, a novel detection and quantification method of control valve stiction is discussed. A time delay estimation method is presented for processes under an oscillating state. A suitable model structure of valve stiction is chosen prior to conducting valve stiction detection and quantification. Given the stiction model structure, a bounded search space of a stiction model is defined an...

Abstract. This work presents a cascade controller for the trajectory tracking control of a hydraulic actuator by using adaptive algorithms to deal with parametric uncertainties together with an adaptive dead-zone compensation scheme. The hydraulic actuator is modeled as a forth order nonlinear system including the valve dynamic as a first order linear system and considering a valve with a dead-...

In steam turbine control and actuation, the valve plays a key role in operability reliability. The electrohydraulic regulating system for valve, usually called servomotor, needs to be reliable high performing under nonlinear excitation interference actual conditions. Currently, servo technology is widely used servomotors. Although this has good performance, it still some technical defects, such...

The major cause of late mortality and morbidity after prosthetic valve replacement is thromboembolism. The nidus for initiation of thrombus formation has been blood metal interfaces, and a new valve--the St Jude prosthesis--has therefore been developed without any metal components. We have assessed echocardiographically in 27 patients the effects of this valve on left ventricular filling charac...

Since knowledge on hydrodynamic torque of a butterfly valve is very important for butterfly valve design, its hydrodynamic torque is investigated in this paper. In reality, the investigation of the loss coefficient and torque from some experiments will take a long time and a lot of money. This paper presents a statistical study of the flow past the butterfly valve in a static analysis using com...