Engineering & Low Pressure Compressors

Engineering sites and low-pressure air processes may both look like high-air-volume applications, but their requirements for an air compressor are actually different. Under the same category, the firstAir brand offers two series: FSG for general-pressure air supply on engineering sites, and FSL for low-pressure high-flow processes whose pressure demand is not high to begin with. Both share the F-prefixed naming and similar structural logic with other firstAir screw series, making it easy to configure a complete set within one brand.

FSG Series: Trade-Offs Made for the Job Site

The FSG Series covers a working pressure of 0.7–1.25 MPa, air delivery of 1.85–32.0 m³/min and a power range of 15–185 kW, using air-cooled cooling and coupling drive. Engineering sites often lack a stable circulating water system, so air cooling removes the water circuit and makes installation and relocation more flexible; coupling drive transmits torque directly from the motor to the airend, giving good structural rigidity and removing a wear part that would need regular tensioning, suited to high-power continuous operation over long periods. Voltage / frequency is 380/50.

FSL Series: The Low-Pressure High-Flow Approach

The FSL Series sets the working pressure at 0.3–0.45 MPa, with air delivery of 6.0–50.8 m³/min and a power range of 30–220 kW. Many plants actually need only low-pressure air, yet supply it from a 0.7–0.8 MPa machine and then reduce the pressure with a regulator; the pressure comes down, but the extra electricity consumed does not come back. The FSL airend is designed for low-pressure duty, delivering greater air output at the same power so the machine does not first do useless compression work. Low-pressure air supply is more sensitive to the pipe network: an undersized pipe diameter brings noticeable pressure loss that cancels out the benefit of a low-pressure model, so selection should be calculated together with the piping design.

Technical Specifications

The FSG Series uses air-cooled cooling and coupling drive, with a voltage / frequency of 380/50.

Selection Points

1. On engineering sites without a stable water source or with frequent relocation, give priority to the air-cooled FSG models;
2. Where process pressure stays below 0.45 MPa over the long term, calculate the running benefit of a low-pressure solution with FSL;
3. Engineering air demand fluctuates greatly, so size the model by peak demand and leave a margin;
4. For a low-pressure solution, calculate pipe network pressure loss and pipe diameter at the same time to avoid cancelling out the energy savings.