Maintenance-free KGVs for Recycled Paper Mills


Abrasive items, such as staples, glass, wires, and plastic, present a challenge in recycled pulp mills and, when trapped within a valve’s interior, can cause jamming.

A large mill in the northeast USA was refurbishing the isolation valves installed on their high-density cyclone cleaners every six to eight months. Each time this occured, they would have to fabricate new parts for the valves at a local machine shop and incur maintenance time and expense.

stafsjo RKO for abrasive media
The RKO's circular inlet and square outlet prevent clogging and blockages.


Armour Valve's proposed solution was the Stafsjö RKO Knife Gate Valve (KGV). Stafsjö’s RKO is reliable and particularly well suited for demanding reject and other abrasive media. The valve’s circular inlet and square outlet, together with the gate, counteract clogging and blockages.

  • This valve is specifically designed for the rigours of cyclone cleaner isolation and reject service.
  • A rectangular outlet with blade guide strips prevents debris from becoming trapped in the valve.
  • The bottom of the blade never fully retracts into the valve chest, leaving little to no chance of foreign objects being pulled into the packing area. This helps to eliminate jamming and maintain the valve’s packing seal integrity.

"Established the Record for being Maintenance Free in the Mill"


Mill personnel decided to test four Stafsjö RKOs in cyclone cleaner isolation and reject service. The valves remained in service for two full years before the seats had to be replaced.

The RKO outperformed other cleaner isolation valves by 2-4 times. Rather than requiring refurbishment every six to eight months, the RKOs only needed periodic packing adjustment, saving the mill considerable time and money.

The Maintenance Superintendent declared that the RKOs: “Established the record for being maintenance-free” in the mill.

The RKO has proven that it outperforms others in demanding service such as cyclone cleaner, detrasher,  pulper isolation, and scavenger applications.

stafsjo RKo features to handle abrasive materials