Piston & Plunger Pumps
Piston and plunger pumps are positive-displacement reciprocating pumps used when you need high pressure, accurate delivery, and reliable performance on demanding duties. They’re common in industrial process, cleaning/washdown, injection, and high-pressure transfer applications.
What are piston and plunger pumps and how do they work?
Both pump types use a reciprocating motion to move a fixed volume per stroke:
• Plunger pump: a solid plunger moves through a stationary seal/packing. This design is widely used for higher pressures because the seal is not moving with the plunger.
• Piston pump: the piston and seal move together within the cylinder, typically used for high-pressure duties but with different sealing arrangements.
In both cases, inlet and discharge check valves control flow direction:
1. On the suction stroke, the chamber expands and draws fluid in through the inlet valve.
2. On the discharge stroke, the chamber contracts and pushes fluid out through the outlet valve.
Typical applications
• High-pressure water systems: washdown, cleaning, jetting (duty dependent)
• Chemical injection / dosing: where high pressure is required (system dependent)
• Process transfer: high-pressure transfer of compatible liquids
• Hydrostatic testing and pressure testing
• Industrial services: oils and other clean fluids where pressure and accuracy matter
(Suitability depends on fluid lubricity, solids content, viscosity, temperature, and required pressure.)
Why buy piston and plunger pumps from Triark?
Triark can support pump selection, spares supply and aftercare—helping you match the right pump type and configuration to your required pressure, flow, fluid properties, and duty cycle, then supporting uptime with service parts and technical help.
Piston & plunger pump spares and service
Common wear/service items include:
• Seals/packing (primary wear components)
• Check valves (seats, balls/discs, springs)
• Plungers/pistons (surface wear or scoring)
• O-rings/gaskets
• Bearings/crankcase oil (model dependent)
Repair and maintenance
Good practice includes:
• Maintain correct lubrication (crankcase oil where applicable)
• Monitor for pressure loss, pulsation changes, or valve noise (often indicates valve wear)
• Keep suction conditions stable to prevent cavitation and valve damage
• Use filtration/strain protection where contamination risk exists
• Replace seals/packing on condition to prevent leakage and plunger/piston wear
