Materials Body Style Pressure Classes
Standard Carbon Steels (A216) – WCB, WCC Buttweld End Class 150 – 2” to 48”
Low Temp. Carbon Steels (A352) – LCB, LCC Top Entry Class 300 – 2” to 48”
Standard Stainless Steels (A351) – CF8M, CF8, Ring Type Joint Class 600 – 4” to 24”
High Temp. Stainless Steels (A217) – WC6, WC9
Duplex & Super Duplex (A995) – 4A, 6A
Nickel Aluminium Bronze – BS EN 1982:CC333G,
Titanium (B637) – Grade C-2
With the LACIER’s range of butterfly valves you have the complete package for its duties including; leak tight quarantine, regulating and flow control along with quick operation in lieu of its 1⁄4 turn design. For many years, valves have been required to operate withstanding the severe conditions of low temperatures like -196°C to provide acute quarantine in industries such as LNG, LPG, liquid hydrogen and liquid oxygen. In more recent years owing largely to the prerequisite for speed of operation the users ‘first choice’ has been quarter turn valves and more commonly the Triple Offset Butterfly Valve.
EVOLUTION OF TRIPLE OFFSET
Due to low operating pressures and non-critical applications, butterfly valves traditionally have been accepted in processes where zero leakage was not a requirement. Attempts to challenge this was followed by leaking of valves and failure of systems resulting in a long held belief by Engineers that butterfly valves as a type should not be used for more demanding operations. As complex concentration functions started to become the custom, valve manufacturers began to develop a more tough design where metal to metal sealing could be used in an endeavor to improve the competence of the butterfly valve. To have any venture in success the new design would need to eliminate the usual sealing method of distortion and resistance. It was this technical query that ultimately established the third offset design with the change to the geometry of the sealing sections initiating the groundbreaking, cost, weight and space saving Triple Offset Butterfly valve.