FAQ: Selecting Compressed Air Drain Valves

Choosing the right drain valve is important for getting the most out of your compressed air system. Drain valves remove condensed moisture during operation. If condensate is not removed, the buildup can have expensive consequences.

Moisture buildup can wash away lubrication, and water getting into places it shouldn’t be can spell disaster. Too much condensate can cause rust and scale buildup and place a lot of stress on your air dryer and other components.

Your drain valve options are varied, and not every drain is suited to every application. Most available valves are rated for the most common temperature, moisture and pressure conditions. Some drains are better suited to dirty applications, and there are many ways to increase efficiency and decrease waste.

Powering Your Drain

Many drains will require their own dedicated power source, this is typically 120V AC, but make sure to read the specifications for your valve. Others can be operated pneumatically using the compressed air of the system they’re installed within. This can affect performance in some cases, where some of the pressure in the system is expelled along with the drain contents.

Automated Drainage

Valves that must be drained manually can slow operation and decrease efficiency. Many options are available to automate the process. Some valves come paired with simple electronic timers that can be set to go off at predetermined intervals. The problem here is that condensate buildup is not always consistent, and having a valve that opens too often, or not enough in a given situation is going to cause performance problems.

The best solution to this problem is to use a no-loss drain valve. These are great because they operate based on the actual volume of moisture which needs drained. Condensate is collected during operation and when the volume reaches capacity, the valve trips to discharge without interrupting compression

Getting Dirty

The orifice is the part of the drain where clogs are most likely to occur, different drains will have different sizes, and different sizes serve different situations. Diaphragm drain valves generally have the largest orifice. A larger orifice also means more air can escape when the valve is open, but it also limits the probability of fouling the drain.

Ball valves are simple drains which are great for dirty applications, where gunk and buildup could quickly gum up a less robust mechanism.Special drain filters, or strainers, should be used in situations where there’s likely to be buildup around the orifice.