Kaeser Complete Control Line Kit Replacement – 403574.0

Kaeser 403574.0 – Complete Control Line Kit

The Kaeser 403574.0 Control Line Kit is a pneumatic control-line assembly used in Kaeser rotary screw compressors. Its primary function is to transmit compressed-air control signals between the compressor’s pressure regulators, control valves, unloaders, actuators, and other pneumatic control components.

Working Process:

During compressor start-up, the pneumatic control circuit establishes the required control pressure. The control lines carry these pressure signals to the appropriate valves and actuators, allowing the compressor to start under reduced-load conditions.

Once the compressor reaches operating speed, the control system changes the pneumatic pressure signal. This signal is transmitted through the control lines to the inlet/unloader mechanism, allowing the compressor to enter loaded operation.

During loaded operation, compressed air is produced by the screw element and delivered to the downstream air system. The compressor continuously monitors operating pressure, and the pneumatic control circuit responds to changes in system demand.

When the required discharge pressure is reached, the control system changes the pressure signal supplied through the control lines. The unloader or inlet-control mechanism responds by restricting the compressor’s air intake. This reduces the compression load and places the compressor into an unloaded operating condition.

When downstream air demand increases and system pressure falls, the pneumatic control signal changes again. The connected actuator or control valve responds, allowing the compressor to return to loaded operation.

The 403574.0 Control Line Kit therefore acts as a reliable pneumatic communication network within the compressor. It does not normally carry the main compressed-air flow; instead, it transfers the smaller control-air signals required for automatic compressor regulation.

References identify 403574.0 as a Kaeser Control Line Kit for rotary screw compressors. A parts listing describes it as a complete control-line kit including screw connection/fitting, confirming that the assembly includes the necessary connection hardware.

The control tubing and fittings are exposed to vibration, pressure fluctuations, temperature changes, oil mist, and continuous compressor operation. Over time, the tubing may become brittle, cracked, kinked, abraded, or contaminated, while fittings may loosen or develop leakage.

A damaged or leaking control line can reduce the pneumatic pressure signal reaching a valve or actuator. This can cause delayed loading, failure to unload, unstable pressure regulation, incorrect valve operation, or increased energy consumption.

During maintenance, the compressor must be stopped, isolated, and completely depressurized before the control-line assembly is serviced. All tubing, fittings, screw connections, and connection points should be inspected for cracks, abrasion, loose connections, contamination, and leakage.

The replacement components supplied with the 403574.0 kit should be installed in the correct positions and routed according to the applicable Kaeser service procedure. Proper routing is important to prevent sharp bends, vibration damage, abrasion, and contact with hot or moving compressor components.

After installation, the complete pneumatic control circuit should be checked for leakage. The compressor should then be operated through its start-up, loading, unloading, and shutdown sequences to verify correct control response.

A leaking or incorrectly connected control line can result in incorrect pneumatic signals and unreliable compressor operation.

Correct maintenance using the Kaeser 403574.0 Control Line Kit helps restore reliable pneumatic signaling, accurate valve actuation, proper load/unload operation, reduced control-air leakage, and dependable compressor performance.

Part Number: 403574.0
Brand: Kaeser
Part Description: Complete Control Line Kit
Component Type: Pneumatic control-line assembly
Included Feature: Screw connections/fittings
Application: Kaeser rotary screw compressors
Primary Function: Transmits pneumatic control-pressure signals between compressor control components
Operating Function: Supports inlet control, unloading, pressure regulation, and pneumatic actuator operation
Main Benefits: Reliable control signaling, accurate valve operation, stable load/unload control, reduced leakage, and dependable compressor performance.

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