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Flowserve continues to demonstrate its commitment to provide superior technology for all rotary valve products.  The NAF-ProCap is a high-tech valve for chips filling, one of the most critical applications at a Pulp Batch digester plant. It’s crucial that this is done in a safe and time-saving way and to control the time of the cooking sequence.

The Capping valve is mounted on top of the Batch digester for automated filling of wood chips in the digester. During the cooking sequence the valve provides tight shutoff to atmosphere.

The unique design of the NAF-ProCap is based on a segmented ball valve. This prevents wood chips from getting stuck between the housing and the ball.

Design and function:

The segment is mounted on an upper and a lower stem. The uniqueness of the design is that each of the stems is mounted in an eccentric hub. The stems can be moved along the valve by rotation of the eccentric hubs.

The upper eccentric hub is used for a one-off manual adjustment of the assembly. This provides the correct load and scraper function between segment and seat.

The lower eccentric hub is automated with a Turnex actuator to lift and load the segment against the seat. This is done during each cooking sequence, thus providing a tight seal on the upstream side of the valve.

After the cooking sequence is completed, the process is reversed.

NAF ProCap Valve Features

• Batch digester capping valve
• PN 16-25 and ANSI 150
• Body in EN 1.4408/ASTM A351 CF8M
• Valve Inspection and Testing acc to API 598
• Unique design uses the eccentric hubs to load the seat and provide tight shutoff.
• Jammer device for locking the valve in open or closed (filling or cooking) position.
• NAF Turnex high performance actuators used for operation and eccentric hub

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NAF ProCap Capping Valve Technical Bulletin (Swedish)

NAF ProCap Capping Valve Technical Bulletin and Product Specification in Swedish.