TM-9-2350-311-20-2

HOWITZER, MEDIUM, SELF-PROPELLED, 155MM; M109A2, M109A3, M109A4 AND M109A5

TECHNICAL MANUAL; UNIT MAINTENANCE MANUAL FOR CAB, ARMAMENT, SIGHTING AND FIRE CONTROL, ELEVATING AND TRAVERSING SYSTEMS AND ASSOCIATED COMPONENTS

DECEMBER 1993

TM-9-2350-311-20-2 - Page 799 of 828

TM 9–2350–311–20–2

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APPENDIX I

HYDRAULIC SCHEMATIC SYMBOLS

This appendix provides the hydraulic symbols used on the hydraulic schematic drawings.

LINES AND LINE FUNCTIONS

LINE, WORKING

LINE, PILOT

LINE, DRAIN

CONNECTOR

•

LINE, JOINING

LINE, PASSING

DIRECTION OF FLOW

LINE TO RESERVOIR

RESTRICTION, FIXED

RESTRICTION, VARIABLE

BASIC VALUE SYMBOLS

PRESSURE REDUCING VALVE

BASIC VALVE ENVELOPE

BASIC VALUE SYMBOL, MULTIPLE

FLOW PATHS

FLOW PATHS BLOCKED IN

CENTER POSITION

MULTIPLE FLOW PATHS (ARROW

SHOWS FLOW DIRECTION)

RELIEF VALVE, SPRING

RETURNED

CHECK VALVE

MISCELLANEOUS COMPONENTS

DIRECTION OF ROTATION

(ARROW IN FRONT OF SHAFT)

COMPONENT ENCLOSURE

RESERVOIR, VENTED

PRESSURE GAGE

CYLINDER, DOUBLE ACTING

KNOB

MANUAL ACTUATOR, SPRING

RETURNED

SOLENOID

COMPONENT PORT

MOTOR, HYDRAULIC, FIXED

DISPLACEMENT

PUMP, HYDRAULIC, FIXED

DISPLACEMENT

GAS (NITROGEN) –OVER–

HYDRAULIC FLUID

ACCUMULATOR

SWITCH, PRESSURE

FILTER, HYDRAULIC FLUID

MOTOR, ELECTRIC

TRAVERSE LEFT

TL

TRAVERSE RIGHT

TR