Multi-Turn Electric Actuators Durable construction for the toughest applications

Flowserve Limitorque SMB multi-turn actuators: when maximum service life is a must 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. All SMB housings are rugged cast iron. Weatherproof construction is standard; other actuators are available for XP, Navy Class A, and nuclear requirements. Clearly capable The SMB series covers a broad scope of capabilities, producing torque...

A proven performer in the most demanding fields With its durable cast-iron housing, the SMB has long been a mainstay of the nuclear power industry. It was the first actuator to be tested and approved for nuclear power plant reactor containment service. SMB actuators are in service in every major nuclear power generation facility in the world, and on most of the world’s nuclear naval vessels. And while the SMB is a veteran of the nuclear power field, this actuator’s brawn has proved valuable to many other industries as well. It can capably serve in such applications as: • Oil and gas wells and...

Engineered for reliable, long-term performance Encased in a rugged cast-iron housing, the SMB is built for exceptional durability inside and out. At the core of the SMB is a double-reduction gear set (helical and worm), available in several combinations, that assures exemplary performance and eliminates “speed vs. torque” sizing trade-offs. For positive, reliable actuation, a “hammer-blow” feature allows the motor to reach full speed before the load is engaged — enabling the actuator to apply appropriate force to the valve shaft. The power of the SMB is tamed by its automatic torque-limiting...

Motor disengages during handwheel operation; can be declutched for manual operation at any time. SMB actuators offer nuclear, weatherproof, submersible, or explosionproof construction. Optional SB (single-compensating) or SBD (double-compensating) spring assemblies can be added to the gear housing for high-temperature or highspeed applications. Insertable stem nut permits relocation of actuator to another valve without major disassembly. Double reduction (helical and worm) gear set. Position and torque limit switches rated at 600 volts, 6 amps. Breathers, drains, and space heaters available for...

A single family of actuators capable of handling an extraordinarily broad range of applications • SMB-000 and SMB-00 The smaller SMBs contain all of the main features of the larger SMB actuators, but are designed for valves requiring smaller operating torque and thrust. • SMB-0 through SMB-3 These larger SMB actuators are designed to accept larger stem capacities and develop more power. Like other members of the SMB line, these can be safely operated manually in the event of power interruption. • SMB-4 and SMB-5 The SMB-4 and SMB-5 offer unequaled capacity for operating large, high-pressure valves....

Choices to make valve control easier … from near or far The SMB series uses close-coupled pilot devices, such as indicating lights and selector switches, for open, stop, and closed local operation. The SMB’s integrated controls can provide output signals to a control room for remote operation. All SMBs are available with optional integral controls and other features built into the motor/geared limit switch compartment: Options Top-mounted and sidemounted mechanical dial position indicators (MDPI ) adjust for 360 viewing. Control Stations • integral reversing motor controllers • position transmitters...

SMB Standard Product Specification Gear housing Housing material – cast iron or ductile iron XP actuators – suitable for Class 1, Groups C and D, Division 1 service and Class II, Groups E, F, and G Lubrication – MOV long-life EP, NLGI grade 0 grease Mounting base Gear reduction – Double reduction type: worm and helical gearing Supplied to MSS (English taps) standard Worm gear – alloy bronze Worm – alloy steel LPS-129. Color blue standard. Valspar epoxy/polyurethane. Helical gears – heat-treated steel Temperature rating Designation – Example: 60/4P refers to “60 foot-pound – four-pole”. Four-pole...

SMB Commercial and Nuclear Options Product Specification Local continuous position indication Optional handwheels Local position indicator that shows continuous valve position via a dial that is labeled 0-100% OPEN. Indicator is driven by a dedicated gear set that is selected per the application. The SMB-000/0 includes window-mounted dial in MDPI housing bolted on the back of the actuator. The SMB-0-5 includes window-mounted dial in MDPI housing close-coupled to actuator housing. Used to reduce the effort required to operate the handwheel. Local/remote indication Includes three-position selector...

SMB Nuclear Product Specification Gear housing Housing material – cast iron or ductile iron Lubrication – MOV long-life EP, NLGI grade 0 grease Gear reduction – Double reduction type: worm and helical gearing. Worm gear – alloy bronze Worm – alloy steel Helical gears – heat-treated steel Motor Designation – Example: 60/4P refers to “60 foot pound – four-pole”. Four-pole is either 1800 RPM (60 Hz) or 1500 RPM (50 Hz); two-pole is either 3600 RPM (60 Hz) or 3000 RPM (50 Hz). Type – Squirrel-cage induction Power supply – suitable for 3/60/230, 460, or 575; 3/50/380; or 3/50/415. Duty – nominal is...

SMB Performance Ratings Commercial service ratings* Max torque rating Output speed range * Maximum torque rating is output speed dependent. Maximum stem capacity Two-piece nut design (drive sleeve and stem nut) Max threaded One-piece design (drive sleeve) Available motors (ft-lb) and corresponding actuator weights** Available motor Model ** With largest motor and no integral controls.