No trabalho é apresentado o estudo do comportamento de válvulas de controle em regime transitório, com base num modelo de cálculo que utiliza o método das características para resolver as equações básicas que simulam o escoamento numa rede de condutos forçados. A simulação da válvula de controle automática e adaptada ao controlador do tipo pid (proporcional, integral e derivativo) visando representar o controle da válvula. São propostas rotinas de cálculos para a determinação da lei de resposta que a válvula de controle deve gerar para atenuar condições transitórias do escoamento. São sugeridos procedimentos de ensaios e testes com os controladores para se obter dados para o projeto e instalação dessas válvulas em redes hidráulicas complexas.

This paper promotes a study on the behaviour of control valves during unsteady flow. This study has its basis on the developement of a numeric mathematical modell. The modell uses the method of characteristics to solve the basic equations of fluid mechanics, the equation of continuity and the equation of motion, simulating the fluid flow in pipe networks. We proposed a modell to simulate automatic or motorizes control valves in conjunction with this methodology. The necessity to use this systems, assuring the correct installation of this valves in hydraulic networks, is emphasized, to make this arrangement compatible with the networks maneuvers. This compatibility must exist during steasy flow, and also during the time intervalo f unsteady flow. The manufacturers of automatic control valves must take attention to this study, supplying theiers catalogs with the information that we need, in order to make the simulations of theier equpments possible and reliable. We adjust a PID (Proportional, Integral and Derivative) controller to represent the pilot systems of this arrangement in order to make the behaviour of the controller versatile. It was proposed, also routines to determine the ideal response that the controll valve generates to minimize a pressure wave. This ideal law is the basis for digital control systems. This modells uses a intensiv processing procedure to obtain the maneuvers that will be impose to the valves when unsteady flow occurs. We suggest experimental layouts to test this equipments, we recommend boundary conditions, and tests with oder types of controllers to give safe conditions to engineers, when they install this valves in complex control systems.