Page 22 - Linde - HPR-02 Self regulating pump for open loop operation

Controllers. LP. Load Sensing with hydraulic pressure cut-off

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01 02 In addition to the load sensing function the LP-controller offers maximum pressure limitation. Once the system pressure reaches
the set pressure of the pressure cut-off valve, the LS-controller is overridden and the pump swashes back, whilst maintaining the
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system’s regulating pressure. The hydraulic pump remains in this state until the system pressure falls below the set pressure. The
hydraulic pump then returns to normal LS operation.
LP. LS with hydraulic pressure cut-off
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LP
LS2
D1
03 LS1 03
P1
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X
P
05 P X T 05

0 max
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T U L
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The maximum pressure cut-off valve prevents prolonged operation of pressure relief valves installed in the hydraulic system for
Projekt-Name: HPR-02-A2-LP00_Schaltplan_Katalog_v01
protection. This has the following benefits for the hydraulic system: Projekt-Titel:
Dokument-Name: Schaltplan_LP
08 Dokument-Titel: RA3 - P. Schlee 08
Projekt-Ersteller:
>> Operating pressure is maintained >> Minimum power loss
RA3 - P.Schlee
Dokument-Ersteller:
Erstellt am:
16.03.2012 13:30:12
Zuletzt gespeichert: 16.03.2012 14:57:47
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01 02 >> No operation in the overload range 06 07 08 >> Reduced heat and noise generation
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>> Any operating point under the power >> Longer service life of the pump and the
curve remains accessible entire hydraulic system
>> Demand-oriented volume flow generation >> Improved energy consumption of the overall system

LP-characteristic curve LP-controller
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pmax

∆p

1
Qmax
1 Flow Possible maximum pressure control setting ranges
2 Pressure >> 125 - 230 bar
Maximum performance range of the pump >> 231 - 350 bar
Actual power demand of the system
Regulating ∆p >> 351 - 420 bar
Pressure cut-off characteristic

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