Quality, durability, and consistent performance in every combination block design

Combination Blocks

Combination Blocks in Compressed‑Air Systems

In industrial compressed‑air systems, combination blocks (also known as integrated compressor modules) are compact assemblies that merge several key functions of the screw‑compressor system into a single, streamlined unit. These typically include the airend, unloader valve, oil separator, cooler, and in some models, an integrated dryer. Their purpose is to reduce physical footprint, eliminate long piping routes and pressure losses, and increase overall system efficiency.

The operating sequence of these modules generally follows these steps:

• Primary air compression by the airend (main rotor set).

• Passage of compressed air through the internal channels of the module, where the oil is separated from the air by the internal separator unit.

• Pressure and flow regulation via the unloader and automatic control valve, synchronized with a digital pressure sensor for real‑time efficiency optimization.

• In more advanced models, the compressed air is cooled and dried through internal coolers and dryers, enabling the entire assembly to operate as a single, low‑vibration integrated unit.

This modular design enables easier maintenance, quicker installation, and consistent, stable performance in industrial environments such as food processing plants, automotive factories, and CNC lines.

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Red Star — Compact Engineering with High Durability

Red Star is one of the advanced Chinese manufacturers that has gained recognition in recent years for its precisely engineered combination blocks designed for screw compressors. Their products integrate all essential mechanical components into a single aluminum‑cast‑iron housing to keep all oil, air, and cooling pathways fully internal.

Red Star combination blocks are typically compatible with medium‑to‑large airends (ranging from 11 to 75 kW). Each module includes an internal oil‑separator stage and a primary inlet filter, ensuring fully self‑contained air‑tight operation.

Main Red Star series:

• RSC Series: Designed for horizontal screw compressors with high airflow rates; includes a three‑stage oil‑return system that reduces oil consumption by more than 30%.

• RSV Series: Built for compact applications with reduced dimensions and lower weight; features an internal spiral airflow path to virtually eliminate pressure drop.

• RSX Series: The newest ultra‑cooling combination block generation, featuring an internal oil‑air cooler and perforated housing sections for faster heat dissipation. This series incorporates SKF Explorer bearings and fully complies with ISO 8573 ventilation standards.

Across all three series, Red Star leverages a Centric Flow Design that directs air precisely toward the airend core, maintaining maximum discharge temperatures below 85 °C — ideal for continuous 24‑hour operation.

Red Star modules are frequently used in OEM compressors across Asia and the Middle East because they maintain an excellent balance between compact size, low weight, and high efficiency.

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VMC — European Modular Design for Continuous Operation and Intelligent Control

VMC (commonly known for its Italian engineering roots and Eastern European assembly lines) specializes in modular compressed‑air blocks designed for continuous duty and high‑pressure applications. Its primary advantage lies in the full integration of mechanical structure and digital control — each module includes internal pressure, oil‑temperature, and even vibration sensors.

The body of VMC blocks is made from nickel‑coated aluminum‑silicon alloy for exceptional resistance against industrial‑oil corrosion. Oil and air pathways are designed in three separate layers: compressed air exits the airend, oil and separator flow through the second layer, and final cooling occurs in the third. This layered structure ensures superior thermal stability and consistent pressure during long operating cycles.

Main VMC series:

• VM‑Compact Series: An economical, compact model for medium‑production lines; includes triple O‑Ring sealing and short oil‑flow paths for minimized pressure loss. Typically used in the 7.5–22 kW range.

• VM‑Pro Series: Engineered for heavy‑duty industrial applications with discharge pressures up to 13 bar; equipped with helical internal heat exchangers and dual bearings with tolerances below 3 µm.

• VM‑Ultra Series: The most advanced generation, featuring Smart Inlet Control for airflow adjustment based on real‑time pressure and ambient temperature. This model uses nano‑ceramic rotor coatings rated for more than 50,000 hours of performance without efficiency loss.

All VMC modules are built on the principle of “Continuous Flow Integrity,” meaning that airflow remains steady and uninterrupted throughout the internal pathways. As a result, compressors equipped with VMC blocks typically operate at sound levels below 76 dB and maintain stable performance even in high‑temperature environments.

Extended VMC Lineup — VTDM and VDM Series

Following the Compact, Pro, and Ultra series, VMC also offers two specialized families of combination modules designed for precise flow control, anti‑vibration performance, and ease of service in high‑pressure industrial applications: VTDM and VDM.

Both are based on VMC’s modular architecture but deliver significantly higher performance than general‑purpose models.

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VTDM Series — Variable‑Temperature Engineering with Dynamic Flow Control

The VTDM (Variable Temperature Dynamic Module) series is engineered for environments where fluctuating ambient temperature or elevated pressure may disrupt compressor performance. Its objective is to simultaneously control temperature, airflow, and oil‑pressure distribution within a single integrated module.

The internal structure of VTDM includes a three‑layer flow system:

• The first layer distributes incoming air uniformly from the airend to the separator path.

• The second layer channels cooling oil using Thermo‑Balanced Routing.

• The third layer regulates discharge airflow via a Dynamic Flow Valve, keeping pressure fluctuation below 2%.

The housing is built from Al‑Si‑Cu alloy with hard nickel plating for superior heat transfer. Instant temperature sensors activate thermal valves in real time — the basis for the VTDM’s temperature‑controlled modular operation.

These modules are widely used in industries with variable operating conditions, such as pharmaceuticals and food production, where ambient temperature shifts but pressure must remain stable. VTDM models typically reduce energy consumption by around 9% compared to conventional units and maintain noise levels below 70 dB, making them ideal for 24/7 indoor industrial operation.

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VDM Series — Heavy‑Duty Design for Stable Pressure and Rapid Servicing

The VDM (VMC Dynamic Mechanism) series is the mechanically stronger variant, designed for compressors that must operate continuously at constant pressures above 13 bar.

The housing is made from graphite‑treated alloy cast iron for high vibration resistance, while internal air passages are polished and coated with nano‑ceramic material to minimize friction and pressure loss.

VDM uses a Dual Phase Oil Cooling system — oil circulates around the rotor through two independent channels, removing heat from both sides and keeping airend temperatures below 90 °C even in heavy‑duty conditions.

A quick‑service valve is built into the lower section of the module, enabling oil draining and cleaning without fully shutting down the compressor — an essential feature for large industrial plants where downtime results in production loss.

VDM blocks are also equipped with a Vibration Monitor Cell — piezoelectric sensors embedded inside the housing to detect any imbalance in the rotor. These sensors transmit data via RS485 or CANBUS to the compressor’s central panel for real‑time monitoring.

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