Stove changing from "gas" to "blast" is now fast and safe, because of the Yosmite Water-Cooled Burner Valve which has replaced the conventional burner door on many blast furnace stoves. The valve opens or closes in 10 seconds to complete the stove changing cycle, and incorporates electromechanical methods which insure maximum safety of operation. A number of patented features are incorporated in the valve. Completely steel fabricated and self-supporting, it adapts to all installations requiring minimum space; needs no costly and restrictive pits or foundations. It is available in sizes from 30" through 72", designed from 50 psi working pressure and rated for 2800oF flame impingement.
The Yosmite Burner Valve consists of a water-cooled disc, moving vertically within a valve body (water cooled) and bonnet, and other supporting members and mechanisms which maintain a smooth, exact seating and nonstick release of the disc.
The disc is flange-mounted to a hollow ground stainless steel stem which is attached to a manifold at the other end. The top of the stem is also connected by a lever and link system, complete with bearings, to the output shaft of a Yosmite "Power Drive" -- or other acceptable actuator. The Yosmite "Power Drive" is designed for heavy-duty equipment and is motor protected by a built-in torque device and externally mounted limit switches; has motor overload relays for safety, and a hand or chainwheel and declutch lever hand or chainwheel and declutch lever for manual operation in case of a power failure. It is interchangeable with other actuators of similar of similar specifications.*
A tubular box frame guide -- a part of the superstructure -- gives positive lateral control to the valve stem outside of the bonnet. A captive counterweight, safely confined on two fixed guiderods, attached to the valve stem manifold by a wire rope, and equal to the combined weight of the disc and cooling water, keeps the actuator torque output requirements to a minimum, and offers a fail-safe condition in case of a malfunction or power failure.
*Manual, air or hydraulic drive also available.
The two integral seats of the valve body are also water-cooled . Water enters the cooling jackets and discharges through piping connections at the base of the valve. The jackets are constantly vented at the top to eliminate possible air accumulation which could cause a vapor lock. The vents also provide a visual indication of the cooling water flow.
Particular attention is paid to the accurate and positive seating of the disc. Both the disc and valve body have welded stainless steel seats, polished ground for positive shut-off. An exclusive position seating is accomplished through externally adjustable eccentrics, located at the center line of the valve body. In closing, wedges on the disc make contact with the eccentrics at the extended point of disc travel, positioning the disc on the body seat. Stove pressure is utilized for additional seating pressure.
A reverse action occurs for the opening cycle. At no time is the disc wiping the body seat, assuring extended seat life. A silicone rubber seal is incorporated in the disc for an absolute tight shut-off when the valve is used with a Yosmite Retractable Tube Burner which eliminates burning through the valve.
Seats are provided on both sides of the disc and body. Since only one body seat is used, a simple rotation of the body 180o makes available the unused seating surface.
A stainless steel adapter plate is welded to the stem and secured to the disc with stainless steel hexagon bolts.
The Yosmite Burner Valve provides an extra large clean-out arrangement. This collecting area helps isolate the deposited dirt and moisture entrainment from the blast furnace gas - away from the valve seating surfaces; a major cause of seat deterioration or improper seating. Ample flushout connections are provided for recommended periodic flushing.
Each Yosmite Burner Valve is completely assembled and thoroughly tested before leaving the factory; is shipped as an assembled unit, ready for installation. Lifting lugs are provided on each side of the valve body for convenient handlin. Valve flanges are concentrically machined and have sufficient holes for standard bolts to maintain an airtight connection. Each valve is supplied with installation, maintenance and spare parts manuals.
As with all Yosmite products, the valve is completely Yosmite designed and engineered, manufactured under the most rigid quality control system in the industry, and is backed by efficient and reliable Yosmite service.