Sullivan-Palatek UD Series User Manual Download

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COMPONENT DESCRIPTION

point. The valve will automatically reset to its reset pressure point after the excess pressure is relieved. The
pressure relief valve is ASME compliant and rated at 200 psig to match the rating of the tank. It is located on
the upper side (wet side) of the sump tank.

3.5.2

COMPRESSOR DISCHARGE TEMPERATURE (CDT)

SENSOR

This sensor

controls shutdown of the compressor in the presence of high unit discharge temperature. The

sensor is preset at

220°F (104°C) for warning alarm and 240°F (116°C) for shutdown fault. The

sensor probe

is located in the compressor unit discharge outlet side port.

3.5.3

RECEIVER PRESSURE SENSOR (P1)

This sensor protects the compressor if pressure in the sump tank or compressor unit discharge exceeds the

rated pressure. This sensor is the first line of protection in the system followed by the tank relief valve. The
receiver pressure sensor also provides start-up protection against reverse rotation. If the sensor does not

identify a positive pressure at time of start-up, the compressor will shut down to protect the compressor

unit from reverse rotation (anti-start protection – ASP). This sensor is located to the right of the electrical
control panel by the pressure regulating control valve. If the compressor is equipped with optional enclosure,

removal of the access panel located to the right of the electrical control panel will expose the sensor and

regulating control valve.

3.6

AIR/OIL DISCHARGE SYSTEM

After compression, the pressurized air and oil mixture travels to the sump tank where the air and oil is

separated by change of direction and reduction in velocity. The oil is stored in the bottom portion (sump) of
the tank until it is recirculated through the system.

The remaining oil in the air is reduced to 2 ppm by the air/oil separator in the top portion of the sump

tank. Oil removed by the separator collects in the bottom pan of the element and is returned to the low
pressure side of the compressor unit by the scavenger line. After passing through the air/oil separator, the
compressed air then continues through to the minimum pressure valve (MPV).

Initially, the pressure is held by the MPV until the set point of the valve is reached. Once the minimum
pressure is met, the MPV will allow air to pass through to the aftercooler to reduce the temperature of the

air from a nominal 180°F to 100

°F (

°C to

°C). This change in temperature condenses the water so that it

can be removed by a water separator equipped with an electric drain valve. After leaving the water separator,
the compressed air can then begin building pressure in the air system for use.

3.6.1 SUMP TANK (RECEIVER)

The sump tank (also referred to as a receiver, reservoir or separator tank) collects and holds oil to be

circulated through the compressor cooling system. Air and oil discharged from the compressor unit are
separated in the sump tank by change of direction and reduction in velocity. The sump tank is an ASME

pressure vessel rated for 200

psig maximum operating pressure.

3.6.2 AIR/OIL SEPARATOR

The air/oil separator (also referred to as a separator element) separates the majority of the remaining oil in

the air before the air passes through the minimum pressure valve to the aftercooler. The air/oil separator is

located in the upper part of the sump tank under the lid.

WARNING!

DO NOT REMOVE STAPLES! The air/oil separator is supplied with staples in the gaskets to ground the

separator to the sump tank in order to prevent flash fires created by build-up of static electricity.

3.6.3 MINIMUM PRESSURE VALVE (MPV)

The minimum pressure valve maintains the minimum pressure in the sump tank necessary to circulate oil

throughout the compressor, and also prevents reverse airflow into the compressor upon unloading or
shutdown. At start-up, the valve remains closed and no output air is supplied until the minimum pressure is
reached. Once the minimum pressure is reached, the valve will open and allow air to enter the system for use.

At shutdown or unloading, a built-in check valve closes to prevent reverse airflow. The minimum pressure
valve is located on top of the sump tank lid.

3.6.4 SCAVENGER LINE (OIL RETURN LINE)

The scavenger line (also referred to as the oil return line) is a small diameter steel tube that picks up any oil

removed from the air by the air/oil separator. Oil picked up by the scavenger line passes through a sight glass
assembly containing an orifice sized for the compressor and a screen to filter the oil before it is injected back
into the compressor unit. The scavenger line is mounted to a tab located on the side of the tank. The tab
fully supports the weight of the assembly for reduced vibration.