Sullivan-Palatek DC185P3JD User Manual Download

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COMPONENT DESCRIPTION

3.6

CAPACITY CONTROL SYSTEM

The control system is designed to match air supply to air demand and to prevent excessive discharge pres-

sure when the compressor is operating but air is not being used. Control of air delivery is accomplished
both by inlet valve regulation and engine speed control as directed by the adjustable discharge pressure
regulator valve.

COLD START SOLENOID

(OPTIONAL ON SOME MODELS)

PRESSURE

REGULATOR

NOTE:

VENT DOWN TO

2. UNLESS SPECIFICALLY NOTED, INDIVIDUAL PART ORIENTATIONS ARE FOUND ON ASSEMBLY DRAWINGS

1. SOLID PIPE CONNECTIONS REPRESENTED BY THIN LINES.

ATMOSPHERE

VENT DOWN TO

ATMOSPHERE

VENT DOWN TO

ATMOSPHERE

VENT DOWN TO

VALVE

START/RUN

ATMOSPHERE

BLOWDOWN VALVE

GAUGE

PRESSURE

RECEIVER TANK

INLET VALVE

THROTTLE CYLINDER

ATMOSPHERE

VENT DOWN TO

3. UNLESS SPECIFICALLY NOTED, IMAGES OF PARTS ARE FOR REPRESENTATION ONLY, ACTUAL PARTS MAY VARY IN APPEARANCE.

MATERIAL:

DECIMAL: X.X + OR - 0.050

IT IS LOANED SUBJECT TO RETURN UPON DEMAND, IS NOT TO BE USED DIRECTLY OR INDIRECTLY

DRA

PROJECTION

1201 West

SCALE:

TOLERANCES AS FOLLOWS:

DESCRIPTION

THIS DRAWING AND ALL INFORMATION THEREIN IS THE PROPERTY OF SULLIVAN-PALATEK, INC. I

WWW.SUL

SUL

CHECKED BY:

DATE:

DRAWN BY:

FIRST USED ON:

ANGLES: + OR - 1/2 DEG.

DIMENSIONS ARE IN INCHES

UNLESS OTHERWISE NOTED

X.XXX + OR - 0.005

X.XX + OR - 0.020

3RD ANGLE

SIZE

LOW PR

3/28/13

D185P2JD

MFP

AS NOTED

3/28/13

DIAG

JPC

FIGURE 3-6.

CD 00008 DIAGRAM, CONTROL D185P2-P3 SINGLE PRESSURE PNEUMATIC CONTROL (REV 00)

The following discussion explains the operation of the control from a condition of “no load” to a condition

of “full capacity” at working pressure. For the working pressure range of your machine, refer to applicable

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the dry side of the receiver via the pressure regulator valve that when the separator pressure is below the
set point of the regulator valve no pressure will exist in the inlet valve cylinder, and the modulating piston
will be held at the fully-opened position by the pre-load of the modulating spring. Under these conditions,
the inlet valve will remain wide open, causing the compressor to deliver full capacity. As the demand for air
decreases, the receiver pressure will rise, and when this pressure level exceeds the set point of the pres-
sure regulator valve, control signal pressure will be allowed to enter the inlet valve chamber which in turn
will move the modulating piston and the valve plate to a closed condition, thereby throttling the incoming
air. A separate throttle air cylinder controls engine speed. The air cylinder is spring loaded in the full speed
position when there is no air signal from the pressure regulator valve. Whenever less than full capacity is
required, receiver pressure increases, thereby opening the pressure regulator, which allows a pressure
signal to enter the throttle air cylinder and reduce the engine speed until it matches the air requirements
from 100% down to 60%. From 60% down to 0% both engine speed reduction and inlet valve modulation
act together to reduce air output.

3.6.1 INLET

VALVE

The inlet valve assembly is the heart of the control system, which regulates the amount of air entering the

compressor. A separate air cylinder regulates engine speed. From full to approximately 60 percent capacity,
the delivery is controlled by engine speed and a gradual closing of the inlet valve. When unloaded the inlet
valve is closed to prevent atmospheric air from entering the compressor.