SEAT RING FOR BUTTERFLY VALVE

• Main Author: HISADA KOICHI
• Format: Patent
• Language: English
• Published: 10.08.2001
• Edition: 7
• Subjects: ACTUATING-FLOATS; BLASTING; COCKS; DEVICES FOR VENTING OR AERATING; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MECHANICAL ENGINEERING; TAPS; THERMAL INSULATION IN GENERAL; VALVES; WEAPONS

PROBLEM TO BE SOLVED: To approximate the rate of fluid increase to a constant level throughout the whole value opening by improving the flow easiness of fluid at fine value opening, lesson damage to a seat ring by shortening the length of a high- velocity contraction area at fine value opening, and provide a seat ring form with no drop in sealing performance at full value closing. SOLUTION: A centric butterfly value has a structure having the seat ring 3 whose wetted body position and flanged connection portion are all coated in a polymeric material such as rubber. The butterfly value seat ring 3 has an elliptic internal surface 4, and bevels 7 between opposite circular sides 6 and the elliptic internal surface 4. The width of each bevel 7 is continuously changed to provided the smallest ones near to a vertical value stem and the largest one perpendicular to the value stem.