Butterfly Valve Distributors

BM Engineering Supplies provides a wide range of butterfly valves that are a lightweight and cheaper alternative to many other types of valve. They deliver easier installation and significant cost savings compared to ball valves, especially at larger sizes. We can also supply actuated butterfly valves on a next-day basis if you require automation for your process. Our actuated packages include: AtEx Exi and Exd, AS-i and 4-20mA control which can all be assembled, tested and dispatched on the same day.

Butterfly Valves Brands


Based in Genoa, Italy, Unitech SRL are a leading supplier of high quality manufactured valves and products for the process industry. Unitech’s products are produced to 97/23/EC ‘PED’ and 94/9/EC ‘ATEX’ in compliance with ISO 9001:2008 standards. Our long standing partnership means that we can consistently supply quality products from a partner you can trust.

Unitech’s range includes:

  • Steel body valves
  • Ductile iron body valves
  • Wafer pattern valves
  • Lugged pattern valves
  • Split body valves
  • Damper valves
  • Eccentric stem valves
  • ATEX valves
triple offset butterfly valve

Zwick Armaturen

Zwick Armaturen has 30 years experience in designing and manufacturing valves of the highest standard. Their triple-offset butterfly valves are used in industries such as oil and gas, chemical, petrochemical, energy, offshore and steel – where critical applications require reliable functionality and 100 per cent zero-leakage.

Zwick’s range includes:

  • Triple-offset Wafer butterfly valves
  • Triple-offset Lugged butterfly valves
  • Triple-offset Double block & bleed valves

If you would like to learn more about the design of a butterfly valve, take a look at our helpful PDF below. You can download this PDF to use at any time.

The design of a butterfly valve



Butterfly valves are often used in agricultural and water or wastewater treatment applications and are one of the most common and well-known valve types.

Butterfly valves are primarily used as a shut-off valve but can be used to regulate flow. A metal disc in the body of the valve is positioned perpendicular to the flow in the closed position, and rotated one quarter of a turn to be parallel to the flow in the fully opened position. Intermediate rotations allow regulation of liquid flow.

The triple offset butterfly valve has three offsets that work together to cut off media. Two offsets are placed to the side of the center, while the third offset is the geometry of the seating surface, creating a type of cone shape of the disc and seat. This cone angle, along with the two eccentric shaft offsets, allows the disc to seal against the seat with no friction.