Vacuum ovens and pumps are a significant investment and important tools in making botanical extracts. And when it comes to extractions, the better you take care of your tools, the better they will take care of you. One of the best ways to protect your investment is to use a trap between your oven and pump.
For botanical extraction, there are three types of traps commonly used: filter traps, cold traps and forline traps. Filter traps and cold traps help prolong the life of oil-free dry-scroll or membrane pumps by capturing the tiny molecules of sticky, gooey extract that make their way out of the oven during a vacuum purge before they make their way into your pump. If unchecked, these particles will build up around the seals and will eventually cause them to fail. Getting back up and running will require a pump rebuild kit and downtime.
The simplest and least expensive trap is the filter trap, which uses air channels and steel wool to create turbulence and cool the exhaust as it passes through. As the exhaust cools, particles will drop out and stick to the steel wool. This is the trap we recommend for butane or propane extractions. For ethanol or CO2 extractions, where moisture must also be removed, we recommend using a dry-ice cold trap to freeze the particles as they pass through.
In addition to increasing the life of the pump, the product collected in the trap can be reclaimed and purged again; waste not want not.
The third type of trap is recommended for use with oil pumps. While we do not believe oil pumps should be used for botanical extraction for several reasons, we know that many people do. For those people, a forline trap is an absolute must.
Unlike the filter traps or cold traps, which are designed to protect your valuable oil-free pump from your product, forline traps are designed to protect your valuable product from your oil pump. Should an oil pump stop running while your oven’s vacuum valve is still open (due to operator error or a power failure), laws of physics will cause the oven to suck air up the exhaust hose, through the dirty, industrial oil in the pump and deposit that filthy oily residue back into the oven.
If that vacuum pump oil makes it into the oven the extracts inside are ruined. The forline trap is intended to prevent that from happening by trapping any oil in the lines. If you’d like to see a video of Mary installing a forline trap on a vacuum oven (and who wouldn’t?), you can check it out here.