WARNING
Incorrect charge pressure settings may result in the
inability to build required system pressure and /or
inadequate loop flushing flows. Correct charge pres-
sure must be maintained under all conditions of opera-
tions to maintain pump control performance.
Loop Flushing Shuttle
Valve
System (Loop) Ports
Loop Flushing
Relief Valve
Loop Flushing Assembly
Loop Flushing Flow
Series 42 pumps may incorporate an integral loop flushing
valve for those applications that require additional fluid to be
removed from the system power loop.
The loop flushing valve will remove heat and contaminants
from the main power loop at a rate faster than otherwise
possible. The loop flushing valve poppet includes an orifice
which removes a set volume of fluid from the power loop. This
fluid is in turn made up by the charge pump.
An assessment of the application cooling requirements and
system cooling capacity should be completed prior to instal-
lation of the components in the application. A flushing flow of
5 to 8 L/min (1.5-2 gpm) is generally suitable for most
applications. Please refer to Sauer-Sundstrand BLN-9886
and BLN-10092 or contact your technical support personnel
for further assistance.
This kit contains two relief valves. The valves are marked with
a 2 or a 3. Valve 2 (Options #2) contains a 1.2 mm (0.047 inch)
orifice, while valve 3 (Option #3) contains 1.4 mm (0.055 inch)
orifice. Using the cooling assessment analysis from above
and the graph at the right, a combination of orifice size and
charge pressure relief setting can be used to obtain the desire
cooling flow.
BLN-10121 contains specific information on the procedure for
installing the relief valve and associated hardware in the
Series 42 pump.
When a Series 42 pump is used with a loop flushing valve
either located in a motor or installed remotely, the setting of
the loop flushing valve should be equal to or less than the
charge pressure setting of the pump.
0
1
2
3
4
5
6
7
8
9
10
0
0.5
1
1.5
2
2.5
0 5 10 15 20 25 30
0 100 200 300 400
Loop Flushing Flow (L/min)
Charge Pressure
(psi)
(gpm)
(bar)
Relief Valve
© Danfoss, 2013 BLN-10122 • Rev AA • September 2013 1
Service Kit Instructions
Series 42
Loop flushing
