Plunger Pump Basic Theory (1/11)

1. Example: Plunger Pump Basic Theory (1/11) A reciprocating positive displacement pump is one in which a piston displaces a given volume at each stroke. A cylindrical solid (e.g. piston) has displaced its volume from the large container to the small container.Volume B (displaced fluid) is equal to the piston volume A

2. Plunger Pump Basic Theory (2/11) All reciprocating pumps have a fluid handlingportion commonly called: Liquid end That has displacing solid called: Plunger or piston A container to hold the liquid called: Liquid cylinder A suction valve to admit fluid from the suction pipe into the liquid cylinder. A discharge check valve to admit flow from the liquid cylinder into the discharge pipe. Packing to seal the joint between the plunger (piston) and the liquid cylinder preventing liquid leaking out of the cylinder and xxx from leaking into the cylinder

3. Plunger moved up Plunger Pump Basic Theory (3/11) Suction stroke Pressure in cylinder reduced When pressure becomes less than that in the suction pipe Suction valves opens Single acting pump Liquid flows into cylinder and fills the volume being vacated by up works movement of the piston Discharge valve is closed by high pressure in the discharge pipe

4. Plunger Pump Basic Theory (4/11) Discharge stroke Plunger moves down causes an increase in Pressure of the liquid contained thein Pressure becomes immediately higher than suction pressure Causes to close suction valve Single acting pump Further plunger movement further rise of liquid pressure When equal to that in discharge pipe discharge valves opens

5. Plunger Pump Basic Theory (5/11) Discharge stroke Liquid flows into discharge pipe Volume =>equal to plunger displacement less small losses Single acting pump

6. Plunger Pump Basic Theory (6/11) Two suction and two discharge valves Double acting pump

7. Plunger Pump Basic Theory (7/11) • Liquid end • Crank - and throw device - Driven by motor electrical Diesel engine (Combuston engine) • Drive gear internal external

8. This type of pump is used when: Dependability is of prime importance even when the pump is operated continuously for long periods an where the pressure is very high. Plunger Pump Theory (8/11) Cast liquid end plunger pumps are used for low and moderate pressure Forged liquid end plunger pumps are used for high pressure

9. Plunger Are made by a number of materials. Plunger must be hard and smooth as possible to reduce friction and to resist wear by the plunger - packing. Hardened chrome alloy steels and steel coated with hard metal alloy or ceramics are must commonly used. Plunger Pump Theory (9/11) Liquid cylinder Commonly made out of forged steel Stuffing boxes and valves chambers Are usually integral with the cylinder

10. Plunger Pump Theory (10/11) Stuffing box Vary widely depending upon service conditions - soft square packing - solid molded rings of square - V lip or U lip Oil and grease can be integrated into a lantern between stuffing box ring to reduce friction and reduce packing and plunger wear.

11. Plunger Pump Theory (11/11) • Very feasible machine • Can operate at any point of pressure and flow within the limitations of the particular design. • The maximum speed of a particular design is primarily limited by the frequency with which the valves will open and close smoothly • The pump will operate against any pressure imposed upon it by the system it by the system it is serving. • Maximum pressure rating of a particular design is determinant by the strength of the liquid end.

12. Thank you for your attention ! Plunger Pump Theory