model valvula
  extends fluido;
  parameter Real R = 250000000.0;
  flange a, b;
  Real q;
  Real hs;
equation
  a.h = b.h + hs;
  hs * gamma = if q > 0 then R * q ^ 2 else -R * q ^ 2;
  a.q = q;
  a.q + b.q = 0.0;
  annotation(Diagram(coordinateSystem(extent = {{-148.5, -105}, {148.5, 105}}, preserveAspectRatio = true, initialScale = 0.1, grid = {5, 5})));
end valvula;