By the sea, a compressor faces two things. Salt, which fouls and corrodes everything the machine draws in. And water, more plentiful in sea air, which ends up as condensate in the receiver, dryer and filters. You protect it through its location, a dryer with automatic draining, and closer care of the filters.
Choosing the flow for a yard or marina is covered on our page on the compressor for boatyards. This article is about installation and condensate.
How much water does a compressor make in sea air?
A physical order of magnitude, for guidance only: at 25 °C and 80% relative humidity, one cubic metre of air holds about 18 g of water vapour.
The calculation for a K 75, which delivers 1.1 m³/min at 8 bar:
- Air drawn in per hour at full load: 1.1 × 60 = 66 m³.
- Water coming in: 66 × 18 = about 1,200 g, or 1.2 L per hour.
- Over 8 hours at full load: close to 10 L.
Almost all of that water comes out as condensate, in the receiver, dryer and filters. The figures vary with temperature and humidity, but the order of magnitude shows why a manual drain forgotten for a single day is enough to send water into the network.
Protecting the machine from salt
- A closed, ventilated room, sheltered from rain and spray. Ventilation is still essential: a screw compressor gives off a lot of heat.
- The air intake on the land side, away from the quay, the blasting area and the sanding area.
- The intake filter holds back salt and dust. Check it more often than you would inland and replace it as soon as it loads up: intake filter for screw compressors.
- The cooler. Salt and dust on the fins push the temperature up. Clean it with air, machine stopped. See compressor overheating.
- A mobile compressor such as the M 75 goes under cover every evening instead of spending the night on the quay.
Handling condensate
Drain automatically
An automatic condensate drain goes at the low point of the receiver, at the dryer outlet and under every filter that collects water. A timed drain opens at adjustable intervals. A level-sensing drain only opens when water is present, so no air is wasted. Check it regularly: if it sticks shut, water backs up.
Treat the condensate
Condensate from a lubricated compressor contains oil. Never discharge it into the harbour or the storm drains. Collect it and have it treated. Our article on condensate draining explains the options.
Choose the receiver
With no dryer upstream, or in a damp room, a galvanised receiver resists corrosion better than a painted one. Even galvanised, it still needs draining.
Which setup for which site?
- Fixed marina workshop. A 4-in-1 compressor combines screw compressor, receiver, refrigerated dryer and filtration. The K 75 covers one or two stations; the K 110 delivers 1.7 m³/min at 8 bar. At every service, check the built-in drain and filter cartridge.
- Hard standing. An M 75 on wheels delivers 1.0 m³/min at 10 bar on a 180 L receiver. Add a dryer at the outlet and a drain on the receiver.
- Short season. Before a long shutdown, drain the receiver and dryer so no water sits there all winter.
Maintenance in salt air
First service at 500 hours, then every 1,500 hours, with a reminder on the controller. By the sea, add a visual check of the intake filter and cooler between services. Our service kits group the parts for each model. 2-year warranty, parts available for 15 years.
Describe your site and tools in the configurator or in a quote request: we will suggest the right compressor, dryer and draining.
For your trade: Compressor for boatyards and marinas.