Butterfly valve double offset - UNIWAT Fig. VF791 | Comeval | Philippopoulos s.a.
Butterfly valve double offset - UNIWAT Fig. VF791 | Comeval | Philippopoulos s.a.

Butterfly valve double offset - UNIWAT Fig. VF791 | Comeval

Double Eccentric Butterfly Valve Comeval UNIWAT VF791

The UNIWAT VF791 is a double eccentric double flanged butterfly valve designed for flow isolation and limited throttling in water and neutral fluid applications. It is unidirectional, requiring flow direction to follow the arrow on the body. The double eccentricity reduces disc-seat friction during opening/closing and maintains more consistent operating torque compared to concentric butterfly valves.

Standards and Operational Limits

  • Design: EN 593, EN 12516
  • Face-to-face: EN 558 Series 14 / DIN 3202 F4
  • Flanges: EN 1092-2 type 21/B
  • Pressure: PN10 / PN16 / PN25 / PN40, depending on DN and execution
  • Testing: EN 12266-1
  • Seat Leakage: Rate A
  • Top Flange: ISO 5211
  • Compliance: PED 2014/68/EU, Machinery Directive 2006/42/EC

The product page specifies a basic range of DN100–DN1200 and PN10/16, while the technical file includes configurations for PN25/PN40 and larger DN. Final selection should be confirmed based on DN, PN, and application.

Materials and Sealing

Typical construction: body and disc EN-GJS-450-10 / EN JS1040 ductile iron, body sealing seat from stainless steel, disc sealing seat from EPDM, bushing steel+PTFE, and shaft SS420 or SS431 depending on PN. For PN40, body/disc EN JS1030, shafts 1.4021, and sealing ring EPDM are specified.

Seat Temperature Limits:

  • NBR / Hypalon: -10 to +80 °C
  • EPDM: -10 to +110 °C
  • EPDM HT: -10 to +130 °C
  • Viton: -10 to +170 °C

Applications

Suitable for water works, water supply networks, pumping stations, neutral liquids group 2, and neutral gases group 2 within PED limits. Chemical compatibility requires checking seat, O-rings, temperature, and concentration.

FAQ

When to choose over VF790?
When double-offset design, lower seat friction, and Series 14 flanged body are required.

What actuator options are available?
Gearbox, handwheel, or actuator via ISO 5211, with selection based on DN, ΔP, and torque.

Standard (Options)
  • DIN
Connection (Options)
  • Flanged
Material (Options)
  • EN-GJS-450-10 (EN JS1040)
Pressure Rating (Options)
  • PN 10
  • PN 16
  • PN 25
  • PN 40

Datasheet and documents

Description

Double eccentric double flange butterfly valves, unidirectional, with soft sealing, for isolaton, with certain throttling capability. With ISO flange for easy automation. For use in applications of water works. Tight closure and stable operating torque in time. Epoxy coated. Operated by hand lever, worm gear or actuator.

Specification of the range:

Diverse design combinations by materials of construction, nominal size range (DN100-DN1200), design pressure range (PN10-16), as well as operation style and accessories.

Other typical denominations: Double offset butterfly valves

Applications: Water, gases, etc.

Certifications: PED 2014/68/EU

Certificates

Declaration of Conformity 

EAC 010-UNIWAT 

EAC 032-UNIWAT 

WRAS

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