18
Stroke adjustments
limit maximum
spool travel.
Figure 10c. DG5S4 with Pilot Choke & Stroke LImiter Options
Main Stage
Spool
Adjustments to restrict
pilot exhaust flow.
Free flow through this
check valve when pilot
pressure is directed in.
Adjustable orifice restricts
pilot exhaust flow to slow
main stage spools shift.
Pilot Stage Spool
Pilot Choke Block
Section IV – Pilot Valve Section
A. Spool Type - Pilot Valve Section
To maintain proper control, closed center pilot spools are
normally used on two stage valves. In most cases, a number
“6“ type pilot spool is used.
When a type “4” or “8” main stage spool is used, the number
“6” pilot spool is identified as number “68”. This spool com-
bination requires the pilot valve to be assembled left hand on
single solenoid models. Refer to installation drawing (Table
1) for more information.
The number “7” pilot spool is identified as a number “78”
when a “4” or “8” type main stage spool is used on pressure
centered “D” models.
B. Spool Positioning - PIlot Valve
Section
Pilot spools are positioned within the valve by special spool
arrangements. The three basic pilot valve spool arrange-
ments are spring centered, spring offset and detents. The
following paragraphs (1 through 3) describe pilot spool
arrangements.
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