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Clamping Frame:
The triangular clamping frame with its inner sleeve is supported by the three tie bars fixed to the end and clamping
frames and freely slides between the end frame and the goggle plate seat on nylon sleeve bearings. Bearing seals covering
the nylon sleeves assure clean surfaces and ease of movement at all times. The clamping frame is connected to the end frame by a diaphragm which
serves as an expansion joint to afford the clamping movement while at the same time maintaining a pressure seal between the inside of the valve and the atmosphere.
A dust shield covers the space between the clamping and end frames to prevent dust from entering the expansion joint section. |
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Goggle Plate:
The semi-circular goggle plate is supported on the top tie bar and freely swings on a sealed nylon sleeve bearing. A counterweight
is located at the top of the goggle plate and is positioned to place the center of gravity at its pivot point. |
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Goggle Plate Inserts and Seats:
Two inserts are furnished in the goggle plate; one with an opening for the valve "open" position and the second with a blank for the "closed" position.
These inserts are replaceable in the field. To assure a positive seal between the goggle plate and the clamping and stationary frames, a silicone rubber sealing ring is imbedded
in a groove provided on each side of the inserts. The stationary and clamping frame sleeves are furnished
with stainless steel seating rings, machined to assure positive seating when the valve
is placed in the clamped position. |
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Goggle Plate Drive:
A pin arrangement is fastened around the outside of the goggle plate to engage with the plate positioning drive sprocket. This design prevents dust from accumulating in the drive
and also permits constant engagement of the goggle plate with the drive sprocket when clamping and unclamping the valve. TO assure more positive goggle plate positioning in both
the open and closed positions and to provide less operating effort, the sprocket is actuated by a chainwheel or motor driven worn gear reducer. |
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Goggle Plate Positioning Rollers:
To center the goggle plate between the sleeves when the valve is in the unclamped position, positioning rollers are furnished on the stationary and clamping frames. These rollers permit interference-free operation
in that they guide the goggle plate throughout its entire travel and prevent dragging on the silicone rubber seats. They also provide a positive means of breaking the seal between the goggle plate seats and sleeve seating rings when the valve
is being unclamped. This feature prevents the possibility of damaging the seat sealing rings and affords smooth operation.
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Clamping Mechanism:
To move the clamping frame tot he clamped or unclamped positions, three jack screws are furnished between the end and clamping frames -- located near the tie bars
at each apex of the triangle. The jackscrews are connected by bearing mounted rigid shafting and universal joints -- and driven through a bevel gear reducer by a chainwheel or motor operator. To assure uniform seating with the goggle plate rubber seats, the clamping
mechanism is shop adjusted with shims between the end and clamping frames. This jack screw design affords a large clamping force with a minimum effort and dust proof duck reinforced neoprene boots cover the jack screws and universal joints to protect them from the atmosphere. |
