US Patent 7252111 Transport of highly viscous fluids in closed pipeline systems

Apparatus far equilibrating differences between flow rates into and out of closed pipeline systems, which apparatus includes a tank having a supply line and a discharge unit, with a displaceable plate; the supply being fed to the tank through the displaceable plate, the discharge from the tank being through an outlet at the bottom of the tank and the plate moving upwards or downwards to automatically change the volume of the tank in accordance with differences between the supply rate and the discharge rate.