BUTTERFLY TYPE PRESSURE CONTROL VALVE

To provide a butterfly type pressure control valve which is disposed at an exhaust side of a vacuum chamber of a vacuum treatment device, heats a flapper and a periphery of the flapper with a heater to prevent adhesion of products, enables a high speed opening/closing operation while achieving reduction of its thickness and weight to the minimum even if its diameter is increased, can secure maximum conductance when fully opening, and also achieves good assemble ability.SOLUTION: A butterfly type pressure control valve includes: a stem 31 in which shaft parts 41, 42 are provided at upper and lower parts of a stem flange part 40; an annular body 32 in which through holes 61 are provided at the upper and lower part sides; a stem insertion elongated hole 65 which is formed at the through hole 61 with its long side L oriented in a direction perpendicular to a passage 32a; and a thin flapper 33 which is attached to the stem flange part and rotates at the inner periphery side of the body. The stem flange part is formed by a plane 43, having a width W1 larger than a diameter φD1 of the shaft part, and a thickness H which is equivalent to or smaller than the diameter of the shaft part. The stem flange part may be inserted from the stem insertion elongated hole 65 of the body.SELECTED DRAWING: Figure 4 【課題】真空処理装置の真空チェンバーの排気側に配置してフラッパーとその周囲付近をヒーターで加熱して生成物の付着を防止し、大口径化する場合にも最薄型化と最軽量化を図りつつ高速開閉動作が可能であり、全開時にはコンダクタンスを最大に確保でき、組立性も良好なバタフライ式圧力制御バルブを提供する【解決手段】ステムフランジ部４０の上下部にシャフト部４１、４２を設けたステム３１と、貫通穴６１を上下部側に設けた環状ボデー３２と、貫通穴６１に流路３２ａと垂直方向に長辺Ｌを向けて形成したステム挿入長穴６５と、ステムフランジ部に取り付けられてボデーの内周側を回転する薄型のフラッパー３３とを備え、ステムフランジ部は、シャフト部の径φＤ１より大きな幅Ｗ１の平面４３とシャフト部の径と同程度以下の厚さＨにより形成され、このステムフランジ部をボデーのステム挿入長穴６５より挿入可能とした。【選択図】図４