When an actuator offering unsurpassed strength and durability is required, choose a three-decade veteran of the nuclear power industry, the Flowserve Limitorque SMB Series. Extraordinarily solid construction gives these actuators a proven service life of more than 30 years. Weatherproof construction is standard, other actuators are available for XP, Navy Class A and Nuclear requirements.
The SMB series produce torque ranging from 20 to 81349 Nm and handling stem thrusts up to 2224 kN. As a result, the Limitorque SMB family makes valve control easier whenever the application demands maximum durability. SMB and SB Series actuators easily operate all types of valves: gate, globe, plug, ball, and butterfly valves, and specialized valves and mechanisms. The housing is durable cast-iron or ductile iron, acceptable for use in the nuclear power industry as well as other industries.
Spring-compensated versions of the SMB (designated SB and SBD), are available for applications where thermal expansion may pose a jammed-valve risk, or where valve discs are subject to extremely high-speed closure.
Advantages
Rugged cast-iron housing suitable for an exceptional durability inside and out. There´s a double-reduction gear set (helical and worm) inside the SMB, available in several combinations, that assures exemplary performance and eliminates “speed vs. torque” sizing trade-offs.
Positive and reliable actuation, a “hammer-blow” feature allowing the motor to reach full speed before the load is engaged. The power of the SMB is tamed by its automatic torque-limiting feature, which de-energizes the motor in the event of an obstruction to prevent damage to the valve.
A geared limit switch controls valve travel during both opening and closing movements of the valve stem (the limit switch also activates position indicator lights for “open” and “closed” status). The position and torque limit switches are housed in a compartment designed to give technicians easy access to the switches and wiring terminals for simpler installation, startup, and maintenance.