Atlas Copco 1089062052 (1089062119) Solenoid Valve

Part Number Evolution

The 1089062052 is the current active part number for a solenoid valve that previously carried the designation 1089062119 in the Atlas Copco catalog. This is not a redesigned or upgraded component — it is the same valve body, the same coil, and the same technical solution. Atlas Copco updated the catalog numbering system, and the 1089062052 became the official replacement entry. When you order the 1089062052, you receive the identical valve that once shipped under the older code.

For maintenance teams managing mixed-age fleets, this means the 1089062052 drops into any machine that originally specified the 1089062119. The electrical connector, mounting bracket, and port threads remain unchanged. No adapter plates, no rewiring, and no controller reprogramming is needed.

Function Within the Compressor

Inside an oil-injected screw compressor, the 1089062052 controls two critical operational sequences. The first is loading and unloading. When the controller commands the compressor to produce air, the 1089062052 opens to deliver control air to the inlet valve actuator. The actuator opens the inlet valve, and the compressor begins drawing ambient air into the airend. When system pressure reaches the set point, the controller de-energizes the solenoid, the inlet valve closes, and the machine transitions to unloaded idle.

The second function is pressure venting. On shutdown, the 1089062052 releases residual pressure trapped inside the oil separator tank and control lines back to atmosphere. This depressurization is essential — without it, the compressor would attempt to restart against a pressurized system, causing the main motor to draw excessive starting current and potentially trip overload protection or damage the motor windings.

Normally Closed Design

The NC configuration means the valve remains closed when de-energized and opens only when the coil receives 120V power. This is a safety-critical design choice. During a power failure or emergency stop, the coil loses voltage instantly. The internal spring returns the plunger to its seat, closing the valve in milliseconds. This blocks the control air path, which in turn closes the inlet valve and isolates the compression circuit. The compressor cannot inadvertently restart under load when power is restored.

Electromagnetic Operation

Inside the brass valve body, a solenoid coil surrounds a movable ferromagnetic plunger. When 120V AC is applied to the coil terminals, the resulting magnetic field pulls the plunger upward against spring tension. This lifts the plunger seal off the valve seat, opening the flow path between the inlet and outlet ports. Control air or oil can now pass through the valve to the downstream actuator or vent port.

When voltage is removed, the magnetic field collapses immediately. The spring — selected to provide reliable return force across millions of cycles — pushes the plunger back onto its seat. The seal material seats firmly, blocking the flow path. The transition from open to closed completes within tens of milliseconds, which is fast enough for compressor control logic that typically operates on 0.5 to 2-second cycle times.

Loading Sequence

During a loading event, the compressor controller energizes the 1089062052. The valve opens and routes control pressure to the inlet valve cylinder. The cylinder extends, pulling the inlet valve butterfly plate open. Ambient air enters the airend through the intake filter, and compression begins. The 1089062052 remains energized for the entire duration of the loading cycle, holding the control pressure steady.

Unloading and Shutdown Sequence

When system pressure reaches the upper set point, the controller de-energizes the 1089062052. The valve closes instantly, cutting control pressure to the inlet valve. A separate bleed orifice in the inlet valve actuator vents the trapped control air, and the inlet valve spring pushes the butterfly plate closed. The compressor transitions from loaded operation to idle, consuming minimal power until the next loading signal.

On commanded or emergency shutdown, the 1089062052 also opens a vent path that bleeds the oil separator tank pressure to atmosphere through a blowdown silencer. This depressurization step prepares the compressor for a low-torque restart in the next cycle.

Material and Manufacturing Precision

The brass body of the 1089062052 is precision-cast and machined to micron-level tolerances on the internal valve seat and plunger bore. Brass offers three advantages over generic cast iron or zinc alloy alternatives. First, it resists corrosion from compressor lubricant vapors and acidic condensate byproducts that accumulate in the control air circuit. Second, its thermal expansion coefficient matches the plunger seal material, maintaining a consistent seal across the full 0°C to 70°C operating range. Third, its higher density reduces vibration-induced wear on the plunger guide surfaces.

Generic replacement valves often cut costs by substituting materials or loosening machining tolerances. A valve seat that is 0.05 mm out of round may seal adequately when new but will develop internal bypass within a few thousand cycles as vibration and thermal cycling accelerate seat wear.

Coil Quality Under Continuous Duty

The 1089062052 coil operates under extended hold conditions during normal compressor loading cycles, which can last 30 minutes or longer in applications with steady air demand. The genuine Atlas Copco coil uses Class H winding insulation and a copper wire gauge selected for minimum resistive heating at 120V 60Hz. Inexpensive replacement coils frequently use thinner gauge wire and lower-grade insulation. Under sustained hold, these coils overheat, causing insulation resistance to drop until the winding shorts internally.

System-Level Protection

A solenoid valve that fails open leaves the compressor permanently loaded, wasting energy and risking over-pressure faults. A valve that fails closed prevents loading entirely, halting compressed air production. Either failure mode causes unplanned downtime. The 1089062052, built to factory specifications and quality control, minimizes both risks through consistent actuation force, proper seal materials, and verified response times across its rated pressure range.

If you need other Atlas Copco air compressor valves, we provide more models in the table below or you can submit your requirements to us directly.