Sequence Of Events - Vertical Express I-2 Manual

I-2 / I-3 Valve

Sequence of Events

Up Valve Section
Relief Pressure Adjustment Screw
Up Slow
Solenoid
(Closed)
Up Slowdown
Adjustment
Pressure
Control
Piston
Up Stop Adjustment
Up Pilot Piston
Up Fast Solenoid (Open)
Up Start Adjustment
Up Leveling Speed Adjustment
August 2019 - 89130 v.3.0
• Consists of an up leveling speed adjustment, a check valve piston, a regulator piston,
and a relief valve.
• Provides acceleration to full speed, slowdown to leveling speed, hydraulic stopping,
and high-pressure relief for the car in the up cycle.
• Operates in the following sequence:
1. To start the car, the pump starts, and the up fast solenoid energizes. See Figure 6
below and Figure 7 on page 56.
2. The regulator piston is held open by its spring and also the pump pressure on the
face of the piston against the low pressure adjustment. At the beginning, all of the
oil bypasses to the tank past the regulator piston, through the up start adjust-
ment, and to the up stop adjustment.
3. The up start adjustment is open more than the up stop adjustment, making pres-
sure build behind the regulator piston and causing it to move toward the closed
position. The open amount of the up start adjustment governs how fast the regu-
lator piston moves and how rapidly the car starts.
4. As the regulator piston closes, pressure from the pump builds up in the valve and
causes the check valve piston to open. This action allows oil to flow from the
pump into the jack.
High-Pressure
Relief Pilot
Low
Pressure
Adjustment
Figure 6 - Up Start Diagram
TANK
Regulator Piston
PUMP
Check Valve
Piston
Reference Material
MAIN FLOW
CONTROL FLOW
JACK
55