Butterfly Valves have been around since the 1800’s albeit somewhat rudimentary metal seated units and it wasn’t until around the 1950’s with the development of suitable elastomer manufacture did we see them take off in just about every market possible. Available from the cheap and cheerful low end low pressures around 150psi to the well engineered industrial styles and high performance type of units. They can be Centric, double eccentric or triple eccentric in design.
Typically they start from 40nb up to 2500nb and depending on the style range from PN 16, PN 25, PN 40, class 150, class 300 and class 600. Depending on the application they can have a variety of soft seats or metal seats. Just like the ball valves they have various local / global approvals for waterworks, gas and petrochemical markets. The majority are lever or gearbox operated for manual operation however they lend themselves for actuation both electric or pneumatic. One possible limiting factor in butterfly valves is that their discs are right in the centre or just off-centre depending on their individual design of the flow path. Usually the higher the pressures the thicker the discs so the flow path can be quite restricted. hence media and CV factors have to be reviewed along with other factors ensuring the correct installation.
Also refer the Industry – Waterworks section for specialty Valves for Desalination plants. We offer a number of styles to suit the various applications and glad to assist in selection.
Most metal body chemical service valves are fully lined giving corrosion resistance and the butterfly type is no exception. Traditionally most are iron bodies with PTFE liner and encapsulated disc. An economical alternative these days is full 316 body PTFE liner and PTFE coated disc. Having a coated and not encapsulated allows for a better flow path. Both data sheets are below for reference. The coated Disc style is only up to 300NB while the encapsulated version is up to 600nb.
General purpose Butterfly valves
DIN 16 Butterfly Valves
DIN 16 Lugged body butterfly valves can be common on imported equipment and replacements difficult to source due to their incompatibility with Australian / PN standards. NOW AVAILABLE IN AUSTRALIA are DIN 16 valves up to 300nb size (others on indent).