Flowserve Introduces Limitorque SMB Electric Actuator
Unsurpassed strength and durability for a wide range of applications
A proven performer in the nuclear power industry, the Flowserve Limitorque SMB multi-turn electric actuator's unsurpassed strength and durability have made it the standard bearer for a wide range of applications, including oil and gas wells, platforms and pipelines; petroleum refining; hydrocarbon and chemical processing; fossil fuel, nuclear, and hydroelectric power generation; water treatment and distribution; and steam distribution.
Now available with a 10-year standard warranty on commercial applications, the Limitorque SMB features an extraordinarily solid construction and cast-iron housings. Available in weatherproof, explosion-proof, Navy Class A, and nuclear constructions, the SMB has demonstrated a proven service life of more than 30 years. The SMB actuator series covers a broad scope of capabilities, producing torque ranging from 15 ft-lb (20 Nm) to 60,000 ft-lb (81,349 Nm), and handling stem thrusts up to 500,000 lb. (2,224 kN), thereby making valve control easier wherever the application demands maximum durability.
The Limitorque SMB was the first actuator to be tested and approved for nuclear power plant reactor containment applications in the U.S. Today the Limitorque SMB is in service in most nuclear power generation facilities throughout the world, and is the actuator of choice for the U.S. Navy.
At the core of the SMB is a double-reduction gear set (helical and worm), available in several combinations, that assures superior 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 SMB to apply appropriate torque to the valve shaft. When the SMB is operated by handwheel the SMB motor gearing is disengaged, but motor operation returns when the motor is energized. The SMB also offers single- or double-compensating spring assemblies (SB) that can be added to the gear housing for high-temperature or high-speed applications.
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. This limit switch also activates position indicator lights for "open" and "closed" status.
The SMB actuator's 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. From end to end, the SMB embodies sensible design and solid construction.
Other features of the SMB include a top-entry stem nut that permits relocation of the actuator to another valve without major disassembly; position and torque switches rated at 600 volts, 6 amps; and available breathers, drains, and space heaters for the control compartment. Integral control packages are also available.
"With a new, 10-year standard warranty and a proven 30-year service life, the Limitorque SMB is the industry's premier electric actuator for critical or severe service applications," said Dave Montgomery, SMB product manager, Flowserve Flow Control, Limitorque Actuation Systems. "The SMB's unsurpassed strength and durability continue to make it the preferred choice for industrial applications around the world."
About Flowserve Corp.
Flowserve Corp. is one of the world's leading providers of fluid motion and control products and services. Operating in 56 countries, the company produces engineered and industrial pumps, seals and valves as well as a range of related flow management services. More information about Flowserve Corp. can be obtained by visiting the company's website at www.flowserve.com.
Source: Flowserve Corp.