Zwick’s design engineers have solved the ongoing problems encountered by the valves on the sulfur plant. On large-diameter pipelines, typical valve problems range from stuck seals to severe valve seat damage (when the valve needs to be operated after a long period of inactivity). The valve should be designated as a steam jacket because this is a mandatory valve requirement of the standard.
In general, standard valves may be suitable for ideal pipelines where there will never be any downtime or bumps, because once the valve’s body temperature reaches the body temperature of hot sulfur or the exhaust gas passing through it, no solidification will be allowed. When the valve body is also cooled due to sulfur cooling, an abnormal situation occurs, which then solidifies in the bearing/shaft area, thus jamming these elements.
Based on international experience, Zwick engineers recommend the use of steam jacketed valves because they can keep critical areas at a constant temperature, thereby eliminating any potential seizure. The company can provide wafer and double flange valves with steam jackets, and we can also use steam tracking valve trims (stem and disc).
Zwick Tri-Con series valves are equipped with bearing protectors, which can reduce the medium entering the critical areas, plus the bearing flushing port, constitute a true cleaning and protection of these critical areas.
The following description highlights the technical differences between the Zwick Tri-Con valve and other types (from double eccentric valve to jacketless valve), which will fail in this type of application.
The Tri-Con series are specially designed process isolation, on/off and control valves. Its wide range of applications is only limited by the actual materials used. In fact, the valves produced by Zwick are suitable for the temperature range of -196ºC to higher to +815ºC . Valves can be manufactured in any machinable alloy form to meet specific customer requirements.
The Zwick Tri-Con series is a triple eccentric valve with a true cone and inner cone design, which can eliminate any friction on the valve seat, thereby eliminating any wear that may cause leakage. For other typical high-performance valves, this is technically impossible, such as a double eccentric design. As time goes by, the final 15-18º friction seal will leak. Double eccentric valves are not suitable for these demanding applications. Therefore, any attempt to use them may lead to problematic results.
Self-centering disc: With its unique self-centering temperature compensation disc, the Tri-Con series structure can ensure the best position of the laminated seal relative to the valve seat. Therefore, interference caused by thermal expansion is eliminated.
Torque transmission with keys: The disc is keyed to the shaft and is not fixed, providing uniform torque transmission and eliminating the risk of pins falling off.
Ideal film and disc design: The solid disc and its elliptical supporting surface provide the best film fixation effect. Through special processing of laminates, zero leakage can be achieved.
Support bearing bushing: The optimal position of the bearing reduces the bending of the shaft. This can ensure two-way sealing under the maximum pressure.
Post time: Mar-15-2021
