Danfoss PVFC User guide

MAKING MODERN LIVING POSSIBLE

Tech Note

LS Compensating Valve
PVFC

This Tech Note introduces LS compensating
valve PVFC. PVFC is an important step towards
the elimination of typical regulation problems
that arise when, for example, PVG is used with
LS-pumps that

y lead an oil flow into the LS-line
y are fitted with a high leakage LS-control

Code number and weight

In the first case PVFC is used as an
LS-controlled pressure relief valve. In the
second case it is used as an LS-controlled
pressure regulator.

PVFC must only be sold together with other
hydraulic components from Danfoss.

Code number Weight (kg)

158H805500 0.8

520L0218 • Rev BC • Nov 2014

Tech Note LS Compensating Valve PVFC

Technical data

Conversion

Dimensions

Max.pressure (bar) Max. flow

cont. int. (l/min)

350 400 3

PVFC is always supplied as an LS-controlled
pressure regulator. If it is to be used as an
LS-controlled pressure relief valve the following
conversion must be made:

1. Remove nipple at ports 2 and 3 (a/flats 22)

2. Reverse spool

3. Fit the spring into port 3

4. Fit nipple with orifice into port 3

5. Fit nipple without orifice into port 2

The port numbers are stamped into the housing.

The numbers 1, 2, and 3 are stamped into the valve housing.
E: G 1/4; 12 mm deep

520L0218 • Rev BC • Nov 20142

Tech Note LS Compensating Valve PVFC

PVFC as LS-controlled
pressure regulator
(standard)

Application

Function

LS-PVG: Connection to LS-port,
PVG LS-P: Connection to LS-port, pump
Tallene 1, 2 og 3 are stamed into the valve
housing

Some LS-pumps have LS-control with high
leakage or a defined “bleed-off”. The oil flow
from the LS-line to tank often causes too low an
LS-pressure in relation to the load pressure.

When the LS-pressure in the LS-P line is less than
the LS-pressure in the LS-PVG line + the spring
pressure, the spool in PVFC is displa-ced so that
oil flows from the pump into the LS-P line.

A: Housing
B: Spool
C: Spring (Spring pressure: 1 bar (14.5 lbf/in2)
D: Orifice

When a standard PVFC is built into the LS-line
between proportional valve and pump, an oil
flow equivalent to the leakage is led into the
LS-line.

The spool cuts off the oil flow again when the
pressure in the LS-P line becomes higher than
the pressure in the LS-PVG line + the spring
pressure. Thus the spool regulates the oil flow so
that the pilot pressure for the LS-control always
matches the load pressure.

520L0218 • Rev BC • Nov 2014 3

Tech Note LS Compensating Valve PVFC

PVFC as LS-controlled
pressure relief valve
(converted)

LS-PVG: Connection to LS-port,
PVG LS-P: Connection to LS-port, pump
Tallene 1, 2 og 3 are stamed into the valve

A: Housing
B: Spool
C: Spring (Spring pressure: 1 bar (14.5 lbf/in2) ).

housing

Application

Function

Other LS-pumps conduct an oil flow into the
LS-line via the LS-control. The oil flow in the
LS-line often causes too high an LS-pressure in
relation to the load pressure.

When the pressure in the LS-P line becomes
higher than the pressure in the LS-PVG line + the
spring pressure, the spool is displaced so that oil
flows from the LS-P line to tank.

When a converted PVFC is built into the LS-line
between pump and proportional valve, an oil
flow equivalent to the flow from the pump into
the LS-line is led from the LS-line to tank.

The spool cuts off the oil flow again when the
pressure in the LS-P line becomes less than the
pressure in the LS-PVG line + the spring pressure.
In this way the spool regulates the oil flow so that
the pilot pressure for the LS-control always
matches the load pressure.

Danfoss

Danfoss
Power Solutions (US) Company

2800 East 13th Street
Ames, IA 50010, USA
Phone: [phone]

Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products
already on order provided that such alterations can be made without changes being necessary in specifications already agreed.
All trademarks in this material are property of the respective companies. Danfoss and the Danfoss logotype are trademarks of Danfoss A/S. All rights reserved.

520L0218 • Rev BC • Nov 2014 www.danfoss.com © Danfoss A/S, 2014-11

Danfoss
Power Solutions GmbH & Co. OHG

Krokamp 35
D-24539 Neumünster, Germany
Phone: [phone]

Danfoss
Power Solutions ApS

Nordborgvej 81
DK-6430 Nordborg, Denmark
Phone: [phone]

Power Solutions Trading
(Shanghai) Co., Ltd.

Building #22, No. 1000 Jin Hai Rd
Jin Qiao, Pudong New District
Shanghai, China 201206
Phone: [phone]