NAF Duball

The NAF Duball DL is a full-bore ball valve which is equally suitable for isolation, on/off and modulating control applications. The NAF Duball DL is supplied as standard in stainless steel or carbon steel but is also available in other materials, such as Duplex, titanium, etc.

The NAF Duball DL is the fourth generation of the Duball portfolio, one of the most proven ball valve portfolios in the industry.
The valve has:

• A spring-loaded stem seal packing that provides a long, maintenance-free and safe operation in automated on/off and control service
• Direct actuator mounting capabilities of the NAF Turnex actuator which provides a high performance, vibration resistant, compact valve package
• A sturdy, blowout-proof stem with a long foot providing a high torque transmission with a minimum mechanical backlash
• A floating ball that provides bidirectional tightness
• The unique Z-trim option that minimizes cavitation and noise and has excellent control characteristics
• An extensive size range, DN 25–400, size 1” to 16”
• An easy-to-service arrangement, due to the off-centre joint face of the valve body, which allows for easy replacement of the ball and seals, without the need for removing the stem and actuator
• Metal seats with a rigid welded overlay of Alloy 6 or alternatively, metal encapsulated, reinforced PTFE seats
• A wide range of optional versions, including fire safe tested versions acc. to API 607/ISO 10497 CE-marked according to Pressure Equipment Directive (PED 97/23/EG) module H, category III. For module H1, category IV contact NAF

Industries:
Bleach Chemicals, Chemical and Liquor, Coatings, Digester, Paper Stock

Reliable two-piece ball valve for a tight shut-off. Can be used for almost all extreme applications.

Flowserve NAF Duball is an excellent solution where media and extreme pressure conditions make severe demands on the design, material and performance. Equipped with NAF’s unique maintenance-free o-ring stem seal design. The floating ball design provides excellent tightness in both directions, even at low differential pressures.

Service-friendly due to the off-centre body split and modular design Flowserve NAF Duball is an integrated part in the NAF control valve package with a unique direct mounting concept. Lots of versions available, such as a solution for green liquors, version with ceramic inner parts and several high-alloy materials.

Technical

• DN 25-400 (1-16″)
• PN 10-40 (ANSI Class 150, 300)