Plunger pump

A plunger pump ( plunger pump ) has a structure similar to a piston pump, but it has, instead of a disk-like an elongated piston of the pump is their name - the plunger (English for: plunger, spool ).

Plunger pumps there are single and multiple effect as well as a differential pump in which the plunger has two different diameters.

Function

By the upward movement of the plunger to open due to the suction effect of the suction valve and the water enters into the pump chamber. During the downward movement, the suction valve closes by its own weight and the pressure valve opens, wherein water is forced into the pressure tube. One problem here is the intermittently water flow, which can lead to strokes in the line. By the pressure of the air chamber is converted into a uniform flow, the trapped air acts as a shock absorber for the water column. The vacuum cylinder also contributes to a steady flow of water. If more water is promoted or the water flow more evenly, more -acting plunger pumps, but most are double-acting, in practice, are used.

Difference to the piston pump

In contrast to a conventional piston, which terminates at its periphery sealed to the cylinder, the plunger acts by displacing the water in the work area due to its own volume. As a gland seal is incorporated in the end of the cylinder.

Other application of the plunger

Plunger previously used as a piston in the internal combustion engines, in which the seal is located in the cylinder wall. This is referred to as a plunger therefore piston without piston ring.

Richard Trevithick used huge plunger in his early high-pressure steam engines, since the sealing of a normal working piston had first been found at elevated operating pressure to be practically impossible. Advances in engineering made ​​possible a little later again the use of normal flask at equal and even higher pressures.