Presentation on theme: "Plunger Pump Basic Theory (1/11)"— Presentation transcript:
1 Plunger Pump Basic Theory (1/11) A reciprocating positive displacement pump is one in which a piston displaces a given volume at each stroke.Example: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 handling portion commonly called: Liquid endThat has displacing solid called: Plunger or pistonA container to hold the liquid called: Liquid cylinderA 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 Pump Basic Theory (3/11) Suction strokePlunger moved upPressure in cylinder reducedWhen pressure becomes less than that in the suction pipeSuction valves opensSingle acting pumpLiquid flows into cylinder and fills the volume being vacated by up works movement of the pistonDischarge valve is closed by high pressure in the discharge pipe
4 Plunger Pump Basic Theory (4/11) Discharge strokePlunger moves down causes an increase inPressure of the liquid contained theinPressure becomes immediately higher than suction pressureCauses to close suction valveSingle acting pumpFurther plunger movement further rise of liquid pressureWhen equal to that in discharge pipe discharge valves opens
5 Plunger Pump Basic Theory (5/11) Discharge strokeLiquid flows into discharge pipeVolume =>equal to plunger displacement less small lossesSingle acting pump
6 Plunger Pump Basic Theory (6/11) Two suction andtwo discharge valvesDouble acting pump
7 Plunger Pump Basic Theory (7/11) Liquid endCrank - and throw device - Driven by motor electrical Diesel engine (Combuston engine)Drive gear internal external
8 Plunger Pump Theory (8/11) 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.Cast liquid end plunger pumps are used for low and moderate pressureForged liquid end plunger pumps are used for high pressure
9 Plunger Pump Theory (9/11) Liquid cylinderCommonly made out of forged steelStuffing boxes and valves chambersAre usually integral with the cylinderPlungerAre 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.
10 Plunger Pump Theory (10/11) Stuffing boxVary widely depending upon service conditions - soft square packing - solid molded rings of square - V lip or U lipOil 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 machineCan 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 smoothlyThe 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 TheoryThank you for your attention !