Danfoss H1 Basic Information

Filtration
The suction filter is placed in the circuit between the reservoir and the inlet to the charge pump as shown
in the accompanying illustration.
Suction filtration
P003 471E
Reservoir
Strainer
Filter
Charge
pump
Charge
relief
valve
to pump case
to low pressure
side of loop
and servo control
W
Warning
Clogged filters can cause cavitation, which damages the charge pump.
We recommend a filter bypass with a filter bypass sensor to prevent damage due to blocked suction
filters.
Charge pressure filtration (full charge pump flow)
For most H1 pumps exist two types of pressure filtration:
•
remote pressure filtration (filter remotely mounted on vehicle)
•
integral pressure filtration (filter mounted to the endcap)
Verify option availability in the size specific technical information. In either case the filtration circuit is the
same with the filter element situated in the circuit downstream the charge pump and upstream of the
charge relief valve such that full charge flow is continuously filtered, as shown in the accompanying
illustrations.
Charge pressure filtration can mitigate high inlet vacuum in cold start-ups and provides fluid filtration
immediately prior to entrance to the loop and the control system. Pressure filtration provides a higher
level of filtering efficiency than suction filtration.
Filters used in charge pressure filtration circuits must be rated to at least 35 bar [508 psi] pressure.
A 100 – 125 µm screen located in the reservoir or in the charge inlet line is recommended when using
charge pressure filtration.
A filter bypass valve is necessary to prevent filter damage and to avoid contaminants from being forced
through the filter media by high pressure differentials across the filter.
In the event of high pressure drop associated with a blocked filter or cold start-up conditions, fluid will
bypass the filter. Working with an open bypass should be avoided.
Remote charge pressure filtration
Ports at the endcap are available to allow for the charge filter to be located conveniently for easy service
and replacement. Care should be taken to minimize the hydraulic pressure drops associated with long
connecting lines, small diameter hoses, or restrictive port adaptors at the filter head or endcap. Ensure
the normal operating pressure drop across the remote filtration in and out ports is sufficiently below the
crack pressure setting of the recommended filter bypass valve.
Basic Information
H1 Axial Piston Pumps, Single and Tandem
System design parameters
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©
Danfoss | April 2017 11062168 | BC00000057en-US0602

Danfoss H1 Specifications

General

Brand	Danfoss
Model	H1
Category	Water Pump
Language	English