High Pressure Relief Valve (Hprv) And Charge Check Valve; Hprv/Charge Check Valve Sectional View - Danfoss H1P 045 Service Manual

Service Manual
H1P 045/053/060/068 Axial Piston Single Pumps
Operation

High Pressure Relief Valve (HPRV) and Charge Check Valve

12 | © Danfoss | June 2020
All H1 pumps have a combination high pressure relief and charge check valve. The high pressure relief
function is a dissipative (heat generating) pressure control valve for the purpose of limiting excessive
system pressures. The charge check function replenishes the low pressure side of the working loop with
charge oil.
Each side of the transmission loop has a dedicated HPRV valve that is non-adjustable with a factory set
pressure. When system pressure exceeds the factory setting of the valve, oil is passed from the high
pressure system loop, into the charge gallery, and into the low pressure system loop via the charge
check.
The pump may have different pressure settings to be used at each system port. When an HPRV valve is
used in conjunction with a pressure limiter, the HPRV valve is always factory set above the setting of the
pressure limiter. The system pressure shown in the order code for pumps with only HPRV is the HPRV
setting.
The system pressure shown in the order code for pumps with pressure limiter and HPRV is a reflection of
the pressure limiter setting:
HPRVs are set at low flow condition. Any application or operating condition which leads to elevated HPRV
flow will cause a pressure rise with flow above the valve setting. Consult factory for application review.
Excessive operation of the HPRV will generate heat in the closed loop and may cause damage to the
internal components of the pump.

HPRV/Charge Check Valve Sectional View

HPRV and Charge Check Valve with Bypass Function (except 045/053)
Relief mode
P003 268
AX152886481964en-000405