One base design, two classic valves, endless customization

Posted by Terri Shipstone on
The square CI Series and round MD Series rotary airlock valves on a black background

Think of our most popular pair of valves as two sides of the same coin. While both are nearly identical in their base design, the CI Series has a square-shaped inlet and outlet, while the MD Series has round openings.

The difference in shapes boils down to the requirements of your system. The CI typically works well in construction applications, while the MD excels in food and pet food, but they are both used across multiple industries. Choose whichever one best fits the equipment above and below the valve because, at the end of the day, they are both designed to provide the most flexible customization.

The CI Series and MD Series valves provide production savings and reduce total lifecycle maintenance requirements. Here’s how.

Tough as nails

Both of these valve series have housings cast in North America, giving them an overall stronger and smoother metallurgy. The internal surfaces are free of cracks, pits, or imperfections where material could get stuck. Its tougher construction also means those cracks won’t form during processing.

A stronger valve doesn’t need to be replaced as often, which is a clear cost-savings for most bulk material processors, particularly with very abrasive material like gravel or cement.

Less air loss

If rotary airlocks and feeders are not properly sealed, they lose compressed air, leading to wasted energy and money for plant managers. With an 8-vane rotor design, the MD and CI series rotary valves ensure proper pressure sealing at the inlet and outlet flange. This minimizes pressure loss throughout the system and improves efficiency.

Intelligent design

An outboard-bearing design protects these valves further by placing the bearings out of the path of materials, which would otherwise damage or contaminate them over time. This placement also protects the bearings in high-temperature applications up to 750°F and application pressure differentials up to 15 PSIG.

Valve components are also CNC-machined to precise tolerances, which eliminates axial shaft movement, seal leakage, and shortened bearing life.


Custom configurations mean greater overall efficiency in your system. Whether it’s from reduced maintenance, better material flow, an extended lifespan, or all three, valves work better when they’re tailored to your application.

The CI and MD valves are available in cast-iron and 304 or 316 stainless-steel. With a whole range of sizing options, rotor configurations and rotor tips, accessories, and interior surface coatings, you can mix and match options to make your valve run as efficiently as possible.

Configure yours today

To start sizing and configuring your rotary airlock valve, get in touch with ACS Valves today. We’re always happy to answer questions and help address your conveying challenges.

Categories: Conveying Systems , Manufacturing