Waters Prep Series Installation And Maintenance Manual page 16

Waters Prep series fluid handling unit
Outlet check
valves (2)
Inlet check
valves (2)
Manual sample
inlet valve
Fluid metering
Solvent selection and proportioning take place on the low pressure (intake)
side of the solvent delivery system.
The fluid handling unit can proportion up to four solvents at a time with a
high degree of reproducibility, even when those solvents compose extremely
disproportionate mixtures. The solvent proportioning valve produces
predictable gradient segments, regardless of solvent compressibility and
system backpressure.
Flow path
Solvents are helium-sparged in their reservoirs and proportioned at the
solvent proportioning valve. They then flow to the pump inlet manifold, where
the flow path branches at two inlet check valves. The pump heads draw
solvent through the valves, moving 500 and 1000 μL with each stroke, with a
maximum flow rate of 150 and 300 mL/min.
From the pump heads, solvents converge at a tee fitting (150 mL) or common
outlet check valve (300 mL) before flowing to a pressure transducer. Flow
continues from the pressure transducer outlet to the system purge valve.
Plunger wash
The fluid handling unit contains an active plunger wash system. This helps
lubricate the plunger, reducing wear, and flushes away any mobile phase or
1-6 Overview
Pump head
Solvent
reservoir
lines (4)
Plunger wash
inlet line
Connectors
and fittings
drawer
Drip tray