Manitowoc National Crane NBT40 Series, Service Manual

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2
NBT40 SERVICE MANUAL HYDRAULIC SYSTEM
National Crane
Published 8-01-2017 Control # 287-11
2-9
Main Control Valve
(with Aux. Hoist)
- 4 Section Valve
Main Control Valve (with Aux Hoist) Item Numbers
Main Control Valve (with Aux Hoist) Port/Hosing
Item Description Item Description Item Description
1 Aux Hoist Relief Valve - Up 6 Aux Hoist Relief Valve - up 11 Gauge Port
2 Tele Cyl Relief Valve - extend 7 Lift Cyl Relief Valve - up 12 Load Sense Bleed-Off
3 Main Hoist Relief Valve - raise 8 Main Relief Valve 13 Standby Pressure
4 Main Hoist Relief Valve - down 9 Load Sensing Relief 14 Check Valve (4 places)
5 Tele Cyl Relief Valve - retract 10 Pilot Supply
Port Description Port Description Port Description
A Outlet - swivel port 4 G Tele Cyl - extend B4 Hose - Dump Valve B1
B Inlet - swivel port 3 H Tele Cyl - retract J1 Plugged
C Lift Cyl - extend J Main Hoist Raise J2 Hose - Dump Valve B2
D Lift Cyl - retract K Main Hoist Down J3 Plugged
E Auxiliary Hoist - up B1 Hose - Dump Valve B4 X1 Hose - Dump Valve B5
F Auxiliary Hoist - down B2 Hose - Dump Valve B3 X2 Hose - Dump Valve B6
6
5
4
A
7
B
C
D
B1
F
E
K
J
H
G
B2
X1 J1
X2 J3 J2 B4
9
8
1
12
11
10
3
2
13
10
14
FIGURE 2-2
7591
Reference Only