Determine Required Working Pressure

Most pneumatic tools operate at 0.5 to 0.7 MPa working pressure at the tool inlet. Allow 0.05 to 0.1 MPa for pipe distribution loss. The majority of site pneumatic supply applications are served by 0.8 MPa (8 bar) models. Applications using large-diameter percussion drills or heavy-duty rock breakers may require 1.0 MPa (10 bar). Select the pressure rating one step above your tool inlet requirement to ensure adequate supply pressure across the distribution system under full load.

Calculate Peak Compressed Air Demand

Sum the free air consumption of all pneumatic consumers that may operate simultaneously. Apply a coincidence factor of 0.6 to 0.8 for mixed-tool applications (not all tools run at peak simultaneously). Add 15 to 20% spare capacity for future expansion and to allow the compressor to top up the air receiver efficiently. The result is your required compressor free air delivery (FAD) in m³/min. Select the model whose rated flow output at your chosen pressure meets or exceeds this figure.

Select Voltage Based on Available Grid Supply

Models up to approximately 200 kW are available with 380 V three-phase motors suitable for standard low-voltage supplies commonly found at industrial sites with low-voltage main distribution boards. Models from 200 kW and above, and many models from 100 kW upward, are better suited to 6 kV or 10 kV medium-voltage supply, which is typical of large mining operations, steel plants, and heavy industry facilities with medium-voltage site distribution networks. Confirm your available grid voltage before specifying a model.

Assess Air Purity Requirements

Standard lubricated models are appropriate for the vast majority of pneumatic tool and construction utility applications where small residual oil content in the compressed air is acceptable and commonly present in pneumatic tool exhaust air. Where the compressed air contacts food products, pharmaceuticals, or sensitive electronic assemblies, the oil-free piston variant must be specified. Confirm application air quality requirements against ISO 8573-1 classes before finalising the specification.

Plan Foundation, Ventilation, and Auxiliary Systems

Reciprocating compressors generate higher vibration levels than screw compressors and require designed reinforced concrete foundations with anti-vibration isolation pads. Larger models (DW and HW series) require substantial foundations — engineering drawings are provided with each order. Ventilation must be sufficient to remove cooling air from the after-cooler and maintain ambient temperature below 40 °C in the compressor room. An air receiver tank sized at minimum 10 times the compressor FAD in litres is required for all installations to stabilise system pressure and reduce load cycling frequency.

In single-stage compression, air is compressed from atmospheric pressure to the final working pressure in one piston stroke. At 0.8 MPa this creates a pressure ratio of approximately 8:1 — generating very high temperatures at the discharge valve (often 200 to 230 °C) and requiring a high specific power input. Two-stage compression divides this into two smaller pressure ratio steps (typically 3:1 in the LP stage and approximately 2.7:1 in the HP stage) separated by an inter-stage cooler. Cooling the air between stages reduces its volume before entry to the HP cylinder, decreasing the work required for the second compression stage. The net result is approximately 10 to 15% lower energy consumption per m³ of air delivered, lower peak temperatures at discharge valves, and extended service intervals for the more thermally stressed components.

Under normal operating conditions with clean, filtered inlet air and correct oil lubrication, the typical maintenance intervals are: inlet and discharge valve plates and springs — 2,000 to 4,000 hours; LP and HP piston rings — 4,000 to 8,000 hours; piston rod packing — 6,000 to 10,000 hours; main and big-end bearings — 15,000 to 25,000 hours. These intervals are significantly longer in clean environments and shorter in dusty or high-humidity conditions. Inlet air filtration quality is the single most important factor in determining valve and ring service life. Regular oil sampling and spectroscopic analysis is recommended for large units to detect early bearing wear before failure occurs.

DW-series machines (60 to 150 m³/min, 13 tonnes and above) require a purpose-designed reinforced concrete isolated foundation. Foundation dimensions, depth, and reinforcement specification are provided in the compressor manufacturer’s foundation drawing package, which is available upon order placement and must be reviewed by a structural engineer before construction. The foundation must be isolated from the building structure by expansion joints to prevent vibration transmission to the building. Anti-vibration mounts between the compressor baseplate and the concrete foundation plinth are standard practice and should be specified as part of the installation package. For HW-series machines (200 to 300 m³/min), a full vibration analysis report is typically required as part of the civil engineering package.

Yes. Multiple compressors of the same model and pressure rating connected in parallel to a common air receiver and distribution header is the standard configuration for large compressed air stations in mining and industrial facilities. This arrangement provides redundancy (continued operation if one unit is taken offline for maintenance), capacity modulation by sequenced starting and stopping of individual units in response to system demand, and flexibility for phased capacity expansion by adding units over time. Each compressor should have its own pressure-adjustable unloading system and isolation valve to allow individual units to be taken offline without shutting down the station. A common station PLC or simple pressure-switch control system can automate the lead-lag sequencing of multiple units.

The prefix letters describe the cylinder arrangement geometry. L-type models (L8, 4L series) use an L-shaped cylinder layout with two or four cylinders at right angles to the crankshaft. LW-type models use an L-type base with a W-configuration cylinder arrangement providing higher volumetric balance and reduced vibration at larger flows. DW-type models use a D-type frame with W-configuration cylinders, providing a longer stroke and larger bore for high-flow outputs in a more accessible maintenance-friendly layout. ZW-type models use a Z-shaped cylinder arrangement suited to compact mid-range outputs. HW-type models (HW-200/8 and HW-300/8) use an H-shaped four-column arrangement giving the highest flow outputs in the series with inherently balanced opposing cylinder forces that minimise net foundation vibration.

All reciprocating compressors produce compressed air containing moisture and, for lubricated models, small quantities of oil vapour. The minimum downstream treatment for pneumatic tool supply is: a properly sized air receiver tank (10 times rated FAD in litres minimum) to buffer demand variation and allow initial moisture dropout; an oil-water separator or automatic drain trap to remove bulk condensate; and an after-cooler if the compressor inter-stage and after-cooling is not sufficient to bring discharge temperature close to ambient. For instrument air or process air applications requiring dry air, a refrigerated compressed air dryer (pressure dew point plus 3 °C) and coalescing filter should be added. For oil-sensitive applications, activated-carbon adsorbers should be installed downstream of the refrigerated dryer to remove residual oil vapour to below 0.003 mg/m³.

Models designated “no base” (such as ZL3.5-20/8 and ZL5.5-40/7) are supplied without the integral baseplate and sub-frame that is standard on most models in the series. These compressors are designed for direct mounting onto a site-constructed reinforced concrete plinth, which is specified in the manufacturer’s installation drawings. Direct plinth mounting provides better vibration damping than a steel baseplate in many large permanent installations and reduces the overall machine height and centre of gravity. The electrical motor and V-belt drive or direct-coupling arrangement is otherwise identical to the baseplate-mounted variants. Foundation design and installation guidance is provided with these models.

The series uses dedicated compressor oil rather than general industrial gear or engine oil. Recommended oil grades are typically ISO VG 100 or ISO VG 150 mineral compressor oil for standard ambient temperature operation (15 to 40 °C). In high-temperature environments (above 40 °C ambient) or for extended oil change intervals, a synthetic compressor oil of equivalent viscosity grade improves thermal stability and extends the drain interval to 2,000 to 4,000 hours versus 500 to 1,000 hours for mineral oil. The specific oil brand and grade recommendations are listed in the operation manual supplied with each unit. Never mix oil types or grades without fully flushing the lubrication system, as cross-contamination can cause varnish deposits on critical components.

Large models with 6 kV or 10 kV motors typically use a star-delta or auto-transformer reduced-voltage starting method to limit inrush current to the site medium-voltage bus. The compressor is started unloaded (inlet valve closed, pressure relief valve open to atmosphere) to minimise mechanical starting torque. Once the motor reaches full operating speed, the starting equipment transitions to the run configuration and the loading sequence begins. For very large motors (above 630 kW), a soft-starter or auto-transformer starter with a longer ramp time may be specified to limit voltage dip on the site bus. Starting equipment is typically supplied and commissioned separately from the compressor by the site electrical contractor. We can provide motor nameplate data, starting current curves, and power factor information for electrical system design on request.

A standard 12-month warranty from commissioning date covers manufacturing defects in materials and workmanship. Extended warranty arrangements are available as service contracts. An initial commissioning spare parts set (piston rings, valve plates and springs, gasket set, oil and air filter elements) is recommended to be ordered with the compressor to ensure parts availability for first scheduled maintenance. Our spare parts catalogue covers all 48 models in the series with standardised part numbers. For large mining and industrial projects involving multiple units, a site spare parts holding agreement can be arranged to ensure critical components are available within 24 hours at the installation site. Contact our technical and logistics team to discuss spare parts supply arrangements specific to your project location.