Heavy-Duty Rotary Airlocks | Built to Be Rebuilt

Rotary Airlock is a broad industry term commonly used to describe industrial bulk material handling equipment that utilizes a rotating-vane device to meter or seal bulk material flow while helping maintain separation between different pressure environments. At PMM, Rotary Valve Airlocks and Rotary Airlock Feeders are distinct product designs engineered for different application requirements.

PMM Rotary Valve Airlocks are constructed from highly durable, abrasion-resistant materials and feature a highly modular design that allows the unit to be broken down into individual subassemblies so applicable wear components can be serviced or replaced in the field. PMM Rotary Valve Airlocks are engineered for a broad range of bulk material handling applications, including high- and low-flow conditions, high-temperature environments, and abrasive, wet, sticky and cohesive materials in powder or granular form.

PMM Rotary Airlock Feeders are also constructed from robust, abrasion-resistant materials and are designed for applications involving oversized, fibrous or stringy materials. They incorporate a helical rotor operating against a hardened tool-steel knife to cut material that could otherwise become trapped between the rotor and housing. PMM Rotary Airlock Feeders are completely rebuildable when returned to PMM’s manufacturing facility in Eugene, Oregon.

The lifecycle savings associated with a rebuildable Rotary Airlock vary by application, operating conditions, maintenance requirements and the extent of the rebuild required. Generally costing approximately 50–75% of the price of a new PMM Rotary Airlock, rebuilding can provide substantial savings compared with purchasing new equipment. When that ability to rebuild and reuse the equipment is extended across multiple service cycles, the cumulative savings over the lifecycle of the Rotary Airlock can become significant.

The economic advantage extends beyond the cost of the rebuild itself. When individual components wear, PMM Rotary Airlocks can be serviced, reworked or rebuilt rather than automatically requiring replacement of the entire unit. This can reduce capital expenditures, maintenance costs and the costs associated with equipment removal, replacement and unplanned downtime.

In one documented chemical-processing application at a Texas facility, the customer reported that a PMM PMV-8 reduced maintenance costs by $60,000 per year while also reducing product loss. The customer also reported that its previous rotary valve cost 12 times as much as the PMV-8 and that using PMM equipment reduced the capital cost of future rotary-valve installations by 85%, due in part to lower equipment cost, a smaller footprint and reduced utility requirements.

Actual rebuild costs and lifecycle savings are application-specific and depend on equipment condition, the components requiring rework or replacement, operating environment and maintenance requirements.

Yes. Every PMM Rotary Airlock that completes a factory rebuild at PMM’s Eugene, Oregon manufacturing facility is returned with a new factory warranty.

During the rebuild, the Rotary Airlock is completely disassembled and each individual component is evaluated against its original factory specifications. Components are reworked to restore them to original factory specifications or replaced entirely as required, with bearings, seals and packing always replaced. Once the rebuild is complete, the Rotary Airlock is returned to the customer with a new factory warranty.

There is no predetermined rebuild interval for a PMM Rotary Airlock. Wear rates vary based on the material being conveyed, throughput, operating hours, temperature, pressure differential, moisture, abrasiveness, internal clearances and other application-specific operating conditions.

PMM recommends monitoring equipment condition and wear rather than relying solely on a calendar-based rebuild schedule. Because PMM Rotary Airlocks are rebuildable, worn components or a complete Rotary Airlock rebuild can be addressed as required and scheduled around a planned outage, rather than waiting for deterioration to progress to the point of critical failure, resulting in unplanned downtime and potentially requiring replacement of the entire unit.

The objective is to address wear before it begins creating broader operational problems such as increased blow-by, reduced airlock functionality, diminished throughput or unplanned downtime.

Yes, depending on the PMM Rotary Airlock design, the component experiencing wear and the extent of service required.

PMM Rotary Valve Airlocks feature a highly modular design that allows the complete unit to be broken down into individual subassemblies. Applicable worn components can be serviced or replaced in the field, with barrel sides and wear plates among the most commonly serviced wear components.

PMM Rotary Airlock Feeders have more limited field serviceability. Packing and bearings can be serviced in the field; however, PMM recommends returning Rotary Airlock Feeders to its Eugene, Oregon manufacturing facility when more extensive wear requires a complete rebuild.

When a complete factory rebuild is required, PMM completely disassembles the Rotary Airlock and evaluates every individual component against its original factory specifications. Components are reworked to restore them to original factory specifications or replaced entirely as required, with bearings, seals and packing always replaced. The rebuilt Rotary Airlock is then returned to the customer with a new factory warranty.