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
It’s not enough for a humidification system to simply add moisture to dry air. Control of relative humidity is essential – even critical – in some applications. Yet, there are a variety of factors and individuals that converge making it complex and challenging to design proper humidification systems.
This white paper, courtesy of Armstrong International, provides important information on all aspects of humidification. Topics Discussed:
Direct Steam Injection (conventional separator type)
Direct Steam Injection (short absorption panel type)
Valve automation dramatically improves control, precision and efficiency. While these advantages
must be weighed against higher capital and operating costs, actuators are frequently found to be a cost-effective investment for most oil and gas applications. This white paper, courtesy of Flowserve, is excellently written and thorough.
BW Series Butterfly Valve For High Pressure Applications
Neles BW series metal seated triple eccentric disc valve is designed for both control and tight shut-off in severe service. Multiple seat options makes it well suited for the refining, power, petrochemical and chemical industries. The BW series provides extended operational life in high cycle, high temperature and abrasive applications.
High Cycling Butterfly Valve, Series BO
Metso Neles BO series butterfly valve is designed for Vacuum Pressure Swing Adsorption plants (VPSA). It is a wafer type, soft seated, high performance, single eccentric disc valve. The valve provides maximal endurance in fast cycling. Additionally, it provides long lasting tight shut off with excellent flow characteristics and high capacity while maintaining the internal tightness even up to 2 million cycles.
High Performance Triple Eccentric Disc Valves, Series L6
Neldisc series L6 triple eccentric disc valve operate both in control and shut-off applications, with close to equal percentage characteristics and superior tightness.
High Performance Triple Eccentric Series L1 and L2
Neldisc series L1 and L2 triple eccentric disc valves operate both in control and shut-off applications, with close to equal percentage characteristics and superior tightness.
High Performance Triple Eccentric Series L12
Neldisc series L12 triple eccentric disc valve operate both in control and shut-off applications, with close to equal percentage characteristics and superior tightness.
High Performance Triple Eccentric Series LW & LG
Neldisc series LW and LG triple eccentric disc valves operate both in control and shut-off applications, with close to equal percentage characteristics and superior tightness.
The Ashcroft P Series pressure control is a precision device which features a snap action switch. Fixed deadband is available with single or dual SPDT independently adjustable switches with various electrical ratings. Adjustable deadband is available with a SPDT switch with various electrical ratings. Several wetted material constructions for compatibility with pressure media may be obtained.
The “P” Series Ashcroft snap action pressure switch is available in explosion-proof NEMA 7 & 9 configurations. The enclosure is an epoxy coated aluminum casting.
This video describes how to calibrate the Ashcroft P-Series.
For more information about Ashcroft, Inc. products, contact: Mead O'Brien https://meadobrien.com (800) 892-2769
Modern electric actuators offer a wide range of technologies and features, from basic motor controls to sophisticated electronic controls. Many choices are available, since no single design or feature set meets the needs of every application.
Actuators are motorized gear drives that control the operation of multi-turn valves, slide gates and dampers; or quarter-turn valves and dampers. Some actuators, including those compared in this paper, use electricity as a power source. Other types of actuators, such as those powered by hydraulic fluid or pneumatic pressure, are not addressed in this paper. Applications vary, requiring the user to select some form of actuator control system. Typical control systems range from simple electro-mechanical controls found in intrusive actuator designs, to solid-state electronic controls found in non-intrusive designs.
The Axiom AN by StoneL an advanced performance, discreet valve controller for quarter turn actuators integrates both state of the art monitoring and robust pneumatic control for use with most on-off automated valves.
The AN was designed for exceptional reliability, universal suitability for most standard control and actuator interfaces, while integrating user friendly advanced technology. This new Axiom platform delivers incredible value over the lifetime of automated valve installations.
The Axiom AN, and all Axiom platforms, undergo extensive crucible and field beta testing, so you can be assured of trouble free performance in harsh conditions and hazardous applications. These tests include a full battery of mechanical, electrical and pneumatic tests, taking place over at least one year. The objective is to accelerate severe process environment conditions so they can assure trouble-free performance over at least one million cycles of operation, and an extended period of time.
Testing is performed internally at the StoneL manufacturing site by independent third party testing organizations, and by nationally recognized hazardous location test labs. Upon successful completion of this testing program, you can be assured of reliable performance in your most challenging process environments. Since we are confident that you will enjoy consistent, reliable performance for many years, the Axiom AN is covered by a comprehensive five year warranty. This warranty covers all mechanical parts and electronics from defects in materials and workmanship five years from the date the unit ships from the factory.
The Axiom AN advanced performance features include an impact resistant, vapor tight Lexan cover, which stands up to most corrosive and heavy washed down environment. The universal pilot, still annoyed, operates with all voltage levels and is suited for temperatures ranging from -40 to 176 degrees Fahrenheit as standard. The switches have touch settings to lock in the limit switch position, and are fully solid state without any mechanical seals. The high flow pneumatic valve offers exceptional tolerance to dirty air and will operate over one million cycles. The larger mechanical visual indicator and brighter electronic high intensity LEDs offer incredible visibility of valve status in dark or brightly lit plant environments.
Like all of the StoneL electronic modules, the Axiom AN C module is fully potted and sealed, preventing contamination from residual moisture and contaminants. The manifold mounting pad attaches directly to most VDI/VDE actuators and features an adjustable spring return or double acting actuator setting for fast field configuration, and a standard re-breather capability that diverts low pressure pneumatic supply air to keep contaminants from damaging the actuator.
And like all Axioms, the AN features a magnetic drive system that provides exceptional long life.
The field proven magnetic drive system offers the most reliable, wear resistant operation on the market. Lateral and vertical shaft movement created by actuator wear has no detrimental effect on the AN drive. There are no seals or bushings to bind. As a result, you can be assured of millions of trouble-free operations. Axiom AN pneumatics feature a standard 5-way, 2 position configuration. Choose from single coil, spring return spool for failing to a predetermined position, or dual coil, shuttle spool for fail in last position.
Like all of StoneL's valve point platforms, the AN was designed to be space efficient by minimizing head room above the actuator and fitting within the actuator dimensional footprint. Mounting kits are designed to adapt the AN to VDI / VDE conforming actuators, as well as most other quarter turn pneumatic actuators. StoneL will design and fabricate kits for your specialized applications on request. Each mounting kit contains manifold, drive coupler, and fasteners for your specific actuator. Kit fasteners and couplers are standard in stainless steel. The mounting manifold is made of anodized and epoxy coated aluminum the same material as the Axiom housing. Please note that the AN mounting manifold is not interchangeable With AMI or AX Axiom platforms.
You can remotely access your automated valves from up to 50 meters when you install the Axiom AN with StoneL's proprietary wireless link app, featuring Bluetooth technology with DEVICENET or AS interface protocols.
10.Ensure the steam boiler is sized large enough to meet the current system consumption and possibly future expansion. Remember: BTUs needed to get feedwater to saturation temperature, and heat loss in piping due to insulation inefficiency.
9.Size steam distribution piping for 6000 FPM velocity below 50 PSIG steam pressure and 8000 FPM velocity for 50 PSIG and above. Remember: lower steam pressure has higher specific volume than higher pressure.
8.Make sure drip legs with drip steam traps are used to remove condensate from steam distribution lines to prevent thermal shock water hammer and poor quality steam delivered to the heat exchanger. Remember: drip legs should be about 2 ft. long and the same size as the steam pipe up to 4” and ½ the size of the pipe above 4”
7.Use equal percentage inherent trim characteristic control valves for process temperature control on steam sized to operate between 20 and 80% open, min to max. Remember: non-linearity in the form of high gain under partial steam load conditions are plotted as the inverse of the =% curve to become close to linear in the installed trim characteristic applied to the process.
6.Use supplemental thermostatic air vents and vacuum breakers (or a single device that does both) on large cavity heat exchangers. Remember: air is an insulator and is detrimental to surface temperature, and vacuum, formed by steam condensing and not replaced with an equivalent volume of steam, prevents the gravity flow of condensate from the exchanger to a steam trap allowing for the potential of thermal shock water hammer and/or internal corrosion.
5.Select the proper steam trap for the application. On modulated steam applications, the F&T (float & thermostatic) steam trap and inverted bucket steam trap are both acceptable depending on performance characteristics desired. Remember: steam traps must 1) stop the flow of steam to allow desired steam pressure to be maintained on the heat exchanger while latent heat is transferred to the process, 2) remove condensate in the heat exchanger simultaneously, and 3) remove non-condensable gases.
4.Ensure the steam trap can provide the capacity at low differential and can overcome static head pressure created by an overhead condensate return. Remember: if that condition can occur, use a mechanical (steam powered) pump as a closed-system in combination with an F&T trap, a double duty type combination device, or a separate open system pump/receiver either mechanical or electric.
3.When the system is operating smoothly and efficiently, look for more ways to increase efficiency by auditing different areas of the generation, distribution, heat transfer, and condensate handling systems periodically and look for opportunities to design and use heat recovery systems. At a minimum, test steam traps once a year for proper operation, but to eliminate the +/- 6 months of lag time between discovery of failed traps at that one moment in time plus the time it takes to arrange and actually repair or replace the steam trap, consider a wireless steam trap monitoring system, at least for the most process-important or highest pressure steam traps that will have the largest steam loss where discovery of failure is within minutes, the system can self-generate a work order, and the repair can be done quickly. One such system utilizes either ISA100 or WirelessHART mesh networks reporting to a measurement, monitoring, and reporting software system designed to manage the system effectively.
2.If you don’t really understand the thermodynamics, proper piping techniques, and potential problems that may occur in your steam system, don’t experiment. Contact someone who has thorough knowledge of steam systems before making that first change.
1.If you do understand your steam heat transfer system, have never instructed someone to “just change out the steam trap, it must be the blame for my system not working correctly since I don’t really know what it does,” then you may be numbered in that new group: “Steam system practitioner, the making of another Prima Donna”.
List courtesy of Steve Huffman, VP of Sales and Marketing, Mead O'Brien.
It’s not enough for a humidification system to simply add moisture to dry air. Control of relative humidity is essential – even critical – in some applications. Yet, there are a variety of factors and individuals that converge making it complex and challenging to design proper humidification systems.
