Goggle Valves
A goggle valve is designed to isolate several components of FCC and Expander Units. Applications for this type of valve are Expander Outlet Line, CO Boiler/Waste Heat Boiler, Flue Gas Cooler, Electrostatic Precipitator, Stack. A goggle valve is an isolation valve suitable for installation in any orientation - horizontal, vertical or inclined.
It is possible to identify six main parts in Remosa's goggle valves.
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Valve body, composed of a main body, an upper bonnet and a lower bonnet.
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Retaining ring, with brackets for the engagement of the hydraulic cylinders piston rod ends. The release movement of the ring is carried out by compression stainless steel bellow. Correct operation of this system is guaranteed by a protective telescopic tube, ensuring dust-free execution. Two optional designs are available: single floating seat or double floating seat. In the first design, only one side of the seat is hydraulically operated to clamp and unclamp the disc. In the second design both seats are hydraulically operated. This second design is recommended for large diameter valves (2500mm ID and above) because of its intrinsic capabilities to accomodate disc deflections or misalingments.
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Disc - made of two main portions connected to allow the disc to slide from fully open to fully closed position.
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Hydraulic circuit; the pressure oil circuit allows the cylinders, connected to retaining rings, to be uniformly moved and also to tighten or untighten the valve disc.
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Motor - it can be hydraulic and pneumatic or electric. Its rotation represents the beginning of a kinematic chain; it is usually provided with emergency mechanical drive section.
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Kinematic chain - through the connection of threaded bars and angular reducers. Threaded bars may be external or internal. The external design will require additional room for the driving system, but it guarantees a better and easier maintenance especially for large size valves.
Both hot wall design and cold wall design can be provided for goggle valve body, depending on customer's requirements. For cold wall design the main body is made of carbon steel plates SA516-Gr. 70 and stainless steel SA240-304H; for hot wall design it is made of stainless steel SA240-304H.
The valve body is made from welded plates, cut and bent at Remosa's facilities. The shape of the valve body is designed to attain the right wall thickness and the lowest possible valve weight. Finite Element Analysis (FEA) is always carried out to assure an optimal and reliable design.
Upper and lower bonnets are made of carbon steel plates SA 516 Gr. 70; calculated thicknesses of valve main plates and stiffening ribs assure high rigidity to the valve body itself.
Remosa's goggle valve actuating process can be summarized as follows:
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The hydraulic power unit - controlled by a local push button or by a remote control system - provides the energy to allow the retracting action of a set of cylinders connected in parallel and acting on the valve retaining ring. Hydraulic Units are available with Manual or fully Automatic Control.
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A retracting action, provided by the parallel of hydraulic cylinders, unclamps the disc and allows its movement to close or to open the valve. Limit switches are installed to detect the complete disconnection between disc and retaining rings and give a permissive for the valve operation.
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The motor operation applies a rotation to a bevel gear that applies a rotation to a kinematic chain. This system allows the internal gears to rotate.
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The disc slides from a position to another (from valve opened to closed or from valve closed to opened) thanks to rack/pinion movement. Motor rotation is automatically stopped by a go switch signal, to indicate the total stroke.
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Actuation of the cylinder pistons firmly clamps the disc in reached position and sealing rings on the clamped disc portion and on the telescopic protective tube prevent any leakage for a perfect seal.
Goggle valves are shipped on a skid manufactured by Remosa to prevent any valve movement.
