Bettis Manual: Operating Instructions M4 Hydraulic Control System | Bettis Manuals & Guides

GH-BETTIS

OPERATING INSTRUCTIONS

M4

HYDRAULIC CONTROL SYSTEM

PART NUMBER: 074950

REVISION: "A"

RELEASE DATE: May, 1991

REPLACES: Service - 085 (Dated 10/87)

GH-Bettis P/N 074950

Page 1 of 3

Revision "A"

SYSTEM DESCRIPTION

The M4 Hydraulic Control System is a compact, modular system designed for use with
GH-Bettis double acting actuators. The system utilizing a bi-directional rotary pump (which
disengages during power operation), individually adjustable speed control and a make up
oil reservoir necessitates by the differential volume of the hydraulic cylinder due to the
piston rod.

The unit must be mounted upright with handle shaft horizontal. The reservoir fill

plug must be removed and replaced with the breather supplied before operation.

POWER OPERATION:

Power operation requires that hydraulic fluid be dislocated during each stroke as the piston
moves within the hydraulic control cylinder. Two individually field adjustable flow controls
integrally mounted in the control module provide controlled opening and closing speeds.
Adjustments are made by loosening the locknut and turning the control valve stem with a
screwdriver. Turn the stem clockwise to decrease the operating speed (increases time per
stroke). Turning the adjustments fully clockwise will prevent fluid flow and actuator rotation
provided fluid relief pressure are not exceeded.

MANUAL OPERATION:

Before attempting to manually operate the M4 bleed off and remove all pressure to the
actuator. NOTE: Make sure both ends of the cylinder(s) are exhausted and vented to the
atmosphere.

Manual operation is accomplished by rotating the pump handle. Clockwise rotation of the
pump handle produces clockwise rotation of the actuator and drives the valve closed.
Counterclockwise rotation of the pump handle produces counterclockwise rotation of the
actuator and drives the valve open.

GENERAL INFORMATION:

The fluid level within the reservoir will fluctuate slightly during operation. Operate the unit
manually while observing the fluid level. It is important that the lowest fluid level not be less
than approximately 1/4 of the reservoir volume. Allowing the fluid supply to be depleted
causes air to enter the system and actuator cylinders. Air in the system will cause the
pump to cavitate, rendering it useless. Erratic speed control characteristics will be noticed.