How often should I drain my air compressor?

Air compressors should be drained daily when in use to prevent moisture build-up. Regular drainage extends the lifespan of the vessel and reduces safety risks.

When does PSSR apply to air compressors?

PSSR applies when an air compressor exceeds 250 bar litres (bar × volume). In these cases, a Written Scheme of Examination and regular Thorough Examinations by a competent person are legally required.

Who can carry out a Written Scheme of Examination (WSE)?

A WSE must be produced by a competent person with the necessary training, knowledge, and experience. Velocity Safety provides WSE creation and PSSR-compliant inspections across the UK.

What happens if I don’t drain my compressor?

Moisture inside the vessel causes corrosion and rust, which weakens the tank walls. Left unchecked, this can result in reduced pressure capacity, rupture, or even explosive failure.

Why Drain Air Compressors? | PSSR Compliance Guide

Air compressors seem like set-and-forget tools – plug them in, pressurise, and get on with the job.

But hidden inside the vessel is a rust time bomb if you’re not draining regularly.

Why Moisture Is a Problem

Every time your compressor runs, it pulls in air – and air naturally contains moisture. That moisture has nowhere to go. It condenses inside the tank, settles, and starts eating away at the steel from the inside out.

Steel + Water = Rust.

Left unchecked, that rust weakens the tank wall, reduces pressure retention, and increases the risk of catastrophic failure. In worst-case scenarios, tanks can rupture – and yes, the result can be explosive.

A “Vengaboys Situation” Waiting to Happen

Ross Ciraolo, our Director, puts it bluntly: “You end up with a Vengaboys situation 💥💥💥💥” – not the kind of bang you want on-site.

To avoid that, draining compressors daily when in use is essential. It’s basic maintenance that massively extends the life of your equipment and reduces safety risks.

It’s Not Just Common Sense – It’s a Legal Requirement

If your compressor exceeds 250 bar/litres in stored energy, you need:

A Written Scheme of Examination (WSE)
Periodic Thorough Examinations by a competent person
Clear maintenance records showing regular drainage and servicing

These requirements fall under the Pressure Systems Safety Regulations 2000 (PSSR) – and no, they don’t have to be carried out by your insurer. We can help develop your WSE, inspect your systems, and keep your site compliant.