Common Causes of Vapour Recovery Unit Failure and How to Prevent Them

Vapour Recovery Unit Maintenance

Vapour recovery unit maintenance has a direct effect on uptime, recovery performance, and emissions compliance. A VRU system that is not maintained properly will usually show signs of trouble before it fails completely.

Most failures are avoidable. They usually begin with small issues that build up over time, especially when the unit is running in demanding field conditions. In many cases, the problem is not one major event but a series of minor issues that were never addressed early enough.

Compressor Problems are a Leading Cause

Compressor maintenance is one of the most important parts of VRU care. Wear on seals, valves, bearings, and lubrication systems can reduce performance and eventually lead to shutdowns.

If the compressor is not inspected regularly, the unit may lose efficiency before anyone notices. That can mean more venting, lower recovery, and higher repair costs later. A compressor that starts out performing well can slowly drift out of spec if routine service is delayed.

Liquid Carryover Creates Serious Damage

One of the most common VRU troubleshooting issues is liquid carryover. If liquids reach the compressor, the result can be damage, poor compression, or repeated trips.

This is why separation equipment has to work correctly. Knockout drums, separators, and drains should all be checked as part of a preventative maintenance plan. Even a small amount of liquid in the wrong place can create a much larger issue downstream.

Sites that see changing temperatures or variable production conditions are often at higher risk. Condensate can build up faster than expected, and if that buildup is not managed, the VRU may begin to perform inconsistently.

Changing Site Conditions Can Overwhelm the System

A VRU may work well when it is first installed, then struggle later if vapour flow rates increase or the gas composition changes. That is especially common when production changes or tanks are added.

If the system was not sized with enough flexibility, it may no longer match the site. In those cases, performance drops even though the equipment itself may still be mechanically sound. The issue is often not failure in the mechanical sense, but mismatch between the equipment and the operating reality.

That is one reason ongoing review matters. A system that was once well suited to the site may need adjustment as conditions change over time.

Preventative Maintenance Reduces Emissions Risk

Preventative maintenance should cover more than mechanical inspection. It should also include control system checks, pressure and flow monitoring, separator and drain inspection, oil analysis, and review of operating data for early warning signs.

That approach helps keep the system reliable and supports emissions compliance. A poorly maintained unit can quickly turn into a venting problem.

For operators, this is where maintenance becomes part of the emissions strategy. A VRU that is consistently inspected and tuned is more likely to remain effective, while a neglected unit can slowly erode both performance and compliance.

What Operators Should Watch For

The warning signs are often subtle. Slower recovery, more frequent alarms, higher discharge temperatures, or a change in cycle behaviour can all point to a problem.

The best approach is to treat the VRU as a production asset, not just an emissions device. When it is maintained well, it lasts longer and performs more consistently. That usually means fewer surprises, fewer shutdowns, and a better return on the original investment.

Call Eagle Pump & Compressor for VRU packages in Alberta and Canada.

Telephone: 403-253-0100