Double flanged butterfly valve also belongs to the quarter family with triple offset design. It is also lightweight and easy to operate. This butterfly valves are torque-seated valves where bubble-tight sealing is achieved when the laminar seal flexes and generates a compressive force all around the hard-faced body seat. 

The materials are cast iron to ASTM A 126 Class B; ductile iron to ASTM A 536 Grade 65-45-12 / GGG40, GGG50; cast carbon steel to ASTM A 216 GR. WCB / A352 LCB / LCC; stainless steel to ASTM A 351 GR. CF8 / CF8M / CF3 / CF3M and duplex steel; aluminum bronze ASTM A148 B95500, C955800 etc. 

Design and manufacture: API 609, BS 5155, MSS SP-67, EN593, MSS SP-68, GB/T12238, AWWA C504;

Testing and inspection: API 598, ISO 5208, BS 6755-I etc;

Face To Face: API 609, ANSI B 16.10, ISO 5752, DIN3202-K1, EN558-1 20 Series, BS5155, MSS SP-67 etc;

Flange Drilling: ANSI B16.5, B16.47, API 605, AWWA C207, EN1092, BS 10 Table / DIN / IS / JIS Std;

Pressure Rating: PN6, PN10, PN16, PN25, PN40, PN63, Class 150, Class 300, Class 600, Class 900.

Leakage Class: ANSI CLASS V & VI (Zero Leakage).

Operation: Up to DN150 lever operated, and above gear operated. On special request available for electric, pneumatic and hydraulic operated.