the promotion of liquefied petroleum gas pump

摘要

A device for pumping liquefied gas, comprises a pump body (3) having a cylindrical bore (5), a piston (15) arranged in the bore of the pump body and axially movable between a front and a back position; a drive means (19, 21) for movement of the piston between the front and back positions. Liquefied gas is flown into the pump chamber as the piston is moved from the front to the back position and is pumped from the pump chamber as the piston is moved from the back to the front position. The pump includes a control means (23) arranged to control (i) the movement of the piston from the front to the back position to be slow enough to substantially avoid boiling of the liquefied gas flown into the pump chamber; and (ii) the movement of the piston from the back to the front position at a variable velocity.