Page 33 - Parker - L90LS Mobile directional control valve

Catalogue HY17-8504/UK Mobile Directional Control Valve
Spool Section L90LS

Port relief and/or anti-cavitation valves [76 A, B]
In spool sections designated **T [47], the cartridge can be used
as a combined port-relief and anti-cavitation valve in the service
ports to protect the valve and consumer from high system pres-
sure and pressure surges.
The cartridge is a direct-acting pressure relief valve with a
very fast opening sequence and good pressure characteristic.
The interchangeable cartridge is factory set. The make-up func-
tion enables oil to flow from the tank gallery to the service-port
side in the event of negative pressure in the service ports, in
order to prevent cavitation.
/ Section not machined for port relief valves.
Circuit diagram for pressure relief valve.
X2 Section machined for port relief valve. Service port open
to tank.
Y2 Section machined for port relief valve. Connection ∆p (bar) Pressure relief characteristic
service ports to tank blocked with plug.
N2 Service ports of section equipped with anti-cavitation
valve.
50-350 Standard pressure settings (in bar) for port relief valves
in A- or B-ports:
50, 63, 80, 100, 125, 140, 160, 175, 190, 210, 230,
240, 250, 260, 270, 280, 300, 320 and 350.

q (l/min)

∆p (bar) Make-up characteristics

Port relief valve

q (l/min)

33 Parker Hannifin
Mobile Controls Division Europe
Borås, Sweden