Providing problem solving and educational information for topics related to industrial steam, hot water systems, industrial valves, valve automation, HVAC, and process automation. Have a question? Give us a call at (800) 892-2769 | www.meadobrien.com
The Armstrong Intelligent Monitoring Model ST5700 is a wireless monitoring technology that efficiently monitors and evaluates steam trap operation. It identifies the conditions of a steam trap to determine significant problems that could put your operation at risk and can accurately detect potential issues such as plugged and blow thru steam traps.
The AIM®ST5700 helps identify the root cause while you minimize production losses and reduce energy consumption. Using non-intrusive technology combined with WirelessHART, the AIM®ST5700 is the ideal solution for any temporary or permanent 24/7 steam trap monitoring.
For more on its operation and use, please read the document below.
In electrical engineering terms, "explosion-proof" or "hazardous" areas are defined as locations where the possibility of fire or explosion exists because of the presence of flammable gasses, liquids, vapors, dusts, or fibers. As a result, electrical equipment must be installed in such a way where any electrical current or signal; a) does not provide enough energy to support an electrical arc (intrinsically safe); or b) is contained in an enclosure and associated conduit that are designed to suppress further ignition by sufficiently cooling escaping gases.
So its important to understand that when describing hazardous area enclosures, "explosion-proof" doesn't mean the enclosure can withstand the forces of an external explosion, but rather that the enclosure is designed to cool any escaping hot gases (caused by an internal spark or arcing contacts) sufficiently enough as to not to allow the ignition of combustible gases or dusts in the surrounding area.
This is a short video that explains what an explosion-proof enclosure looks like, how it works, and why it is safe to use in explosive or combustible atmospheres.
More than 1 million Limitorque actuators have been installed around the world, and some have been in operation for more than 50 years. The ruggedness and reliability of Limitorque electric actuators are among the primary reasons that customers continue to select Limitorque products.
Actuators requiring 90° of rotation to operate are necessary for quarter-turn valves such as ball, butterfly, plug and dampers, and rotary control valves. These types of Limitorque electric actuators are available for operations such as open-close, modulating, network and rotary service.
Multi-turn actuators are required to operate various types of rising stem valves such as gate, slide-gates, globe, check and linear control valves. These types of Limitorque electric actuators are available for operations such as open-close, modulating, network and linear service.
General Safety Precautions
Warning: Read the Installation and Maintenance Manual carefully and completely before attempting to install, operate, or troubleshoot the Limitorque actuator.
Warning: Be aware of electrical hazards. Turn off incoming power before working on the actuator and before opening the switch compartment.
Warning: Potential HIGH PRESSURE vessel — be aware of high-pressure hazards associated with the attached valve or other actuated device when installing or performing maintenance on the actuator. Do not remove the actuator mounting bolts from the valve or actuated device unless the valve or device stem is secured or there is no pressure in the line.
Warning: For maintenance and/or disassembly of the actuator while installed on the valve, ensure that the actuator is not under thrust or torque load. If the valve must be left in service, the valve stem must be locked in such a way as to prevent any movement of the valve stem.
Warning: Do not attempt to remove the spring cartridge cap, housing cover, or stem nut locknut from the actuator while the valve or actuated device is under load.
Warning: Do not manually operate the actuator with devices other than the installed handwheel and declutch lever. Using force beyond the ratings of the actuator and/or using additive force devices such as cheater bars, wheel wrenches, pipe wrenches, or other devices on the actuator handwheel or declutch lever may cause serious personal injury and/or damage to the actuator and valve.
Warning: Do not exceed any design limitations or make modifications to this equipment without first consulting Limitorque.
Warning: Actuators equipped with electrical devices (motors, controls) requiring field wiring must be wired and checked for proper operation by a qualified tradesman.
Warning: Use of the product must be suspended any time it fails to operate properly.
Caution: Do not use oversized motor overload heaters. Instead, look for the cause of the overload.
Caution: Do not operate the valve under motor operation without first setting or checking the limit switch setting and motor direction.
Caution: Do not force the declutch lever into the motor operation position. The lever returns to this position automatically when the motor is energized.
Caution: Do not depress the declutch lever during motor operation to stop valve travel.
Caution: Do not use replacement parts that are not genuine Flowserve Limitorque parts, as serious personal injury and/or damage to the actuator and valve may result.
Caution: Do not lift actuator/gearbox or actuator/valve combinations with only the eye bolts in the SMB actuator. These eye bolts are designed for lifting the SMB actuator only.
General Safety Practices
The following check points should be performed to maintain safe operation of the actuator:
Eye bolts in SMB and SB actuators are designed for lifting only the actuator and not associated gearboxes or valves.
Mount the actuator with the motor in a horizontal plane, if possible.
Keep the switch compartment clean and dry.
Keep the valve stem clean and lubricated.
Set up a periodic operating schedule for infrequently used valves.
Verify all actuator wiring is in accordance with the applicable wiring diagram.
Carefully check for correct motor rotation direction. If the valve closes when open button is pushed, the motor leads may have to be reversed.
Verify the stem nut is secured tightly by the locknut and that the top thread of the locknut is crimped or staked in two places.
Use a protective stem cover. Check valve stem travel and clearance before mounting covers on rising stem valves.
Mead O'Brien Authorized
Blue Ribbon Limitorque Parts & Service
For more information, or if you need field support with any Limitorque actuator, parts, or service, contact one of the following Mead O'Brien offices:
A large University was using magnetic flowmeters (Magmeters) to measure the flow of boiler feed water downstream of a condensate polisher. There were occasional system upsets that required the condensate polisher to be bypassed. When this happened, large amounts of debris would be released downstream and pass directly through the Magmeter, causing a build-up of foreign material on the internal sensing surfaces.
A magnetic flowmeter uses an electric current applied to a coil which produces a magnetic field. When conductive liquid flows through the magnetic field, a small voltage, proportional to the liquid velocity, is induced. As long as the interior surfaces of the Magmeter are clean and unobstructed, the meter accurately measures flow. If they get dirty or coated, all bets are off.
It was in the above mentioned upset situations where the University maintenance people were having problems. When upsets occurred, and the condensate polisher had to be by-passed, it meant the Magmeter would also have to be serviced because accuracy could no longer be guaranteed. Servicing the Magmeter was slow and costly. It meant shutting down the line, draining the pipe, removing the flowmeter, cleaning, and then putting it all back together.
Armstrong International’s Veris Group was called in for a consult. After review, the Veris Group recommended installing an Accelabar® flow meter to offer an alternative solution that could provide reliable flow measurement regardless of an upset condition like unpolished condensate. The Accelabar provided a flow range of 22.5:1 turndown in flow, in a limited straight run scenario. In the past, two transmitters were required to provide the best accuracy across the entire range of the Accelabar. Veris was able to use the Foxboro IDP 10S with its FoxCal™ technology in order to have a combined percent of rate accuracy solution.
The new transmitter installation has 11 separate calibrations loaded into the device. As the differential pressure from the primary element is measured, the transmitter chooses the correct calibration curve. Veris’ solution delivered performance that was previously unattainable with a single differential pressure transmitter.
The Accelabar and Foxboro combined to be best solution, and the Accelabar flow meter is now the University's standard for the boiler feed water measurements.
For more information, contact:
Mead O'Brien, Inc.
10800 Midwest Industrial Blvd
St Louis, MO 63132
314-423-5161
314-423-5707 www.meadobrien.com
