PMA Rubber Tipped Airlock

Precision PMA rubber-tipped airlocks are a heavy-duty, fully fabricated airlock intended for use with mild to moderately abrasive materials where a tight airlock seal is required. 

The PMA product family is well-suited to applications that have proven to be “too much” for conventional rubber-tipped units but where the cost of a heavy-duty feeder or rotary valve is out of reach.  Functionally, the PMA is primarily an airlock but can function as a metering device in some applications.  

PMA Rubber-Tipped Airlock 01

Common Applications

  • Dust collection systems
  • Pneumatic conveying systems
  • Dryer discharge
  • Dust from wood processing
    Sander dust
  • Plastic dust
  • Fiberglass shreds and dust
    Wood fiber

Key Advantages

Barrels are formed of 5/8” mild steel to provide longer life than the gauge material found in many rubber-tipped airlocks – typically 3-4 times longer life before replacement may be considered.

A variety of options for the tip material to suit applications with elevated temperatures or more abrasive materials.

Dodge Type E piloted flange bearings provide superior life over the pressed-fit, sealed-for-life bearings that are common on many other rubber-tipped airlocks.

Problems Solved

Abrasive, heavy-load, or elevated pressure applications where conventional rubber-tipped airlocks wear out too quickly resulting in unplanned downtime or the recurring expense of airlock replacement.

How It Works

The standard configuration includes rectangular inlet and outlet flange.

Formed 5/8” MS barrels and end-plate provide a rigid, long-wearing structure.

Precision-forming of the barrels creates a concentric, uniform diameter that allows for a tight rotor and tips fitment to the barrel. This, in turn, minimizes power draw and promotes even wearing of the rubber tips.

1018 CS drive shaft with ten (10) welded vanes; vanes are gusseted to one another and to the drive shaft to provide structural rigidity for the rotor body.

Standard tip material is a multi-ply hot-asphalt material that is rated up to 450° F.

Tips are installed in a “sandwich” configuration between the vanes and a backer plate and held in place with through bolts.

Heavy-duty Dodge piloted flange bearings.

Nord, SEW, or Sumitomo shaft-mounted gear-motor drive packages for clean, safe installations providing direct application of power with options for variable speeds and other functions.

Options and Upgrades Available

Round inlet and discharge flangesFacilitates easy replacement of existing rotary valves.
Zero Speed SensorsDetect and then alarm or notify that the airlock is not operating.
MSHA/OSHA-Compliant Shaft GuardsOperations and maintenance staff safety

Technical Specifications

Material TypesTypical particle sizes less than ¾” in the major dimension.
Moisture content is typically less than 5%.
Compatible with product temperatures up to approximately 450° F.
As a general rule, no rubber-tipped airlocks, including Precision’s PMA product family, are compatible with the requirements of NFPA 69. Consult the relevant sections of NFPA 69 if there is any question about the application in your plant.
Power RequirementsDrive motors powered by
230/460V 3Ph 60Hz
575V 3Ph 60Hz
Other voltages and frequencies available

Zero speed sensors operate at control voltage.
VFD’s operate single-phase up to system voltage.

Let our applications specialists help you with your extreme-duty bulk material handling needs.