Showing posts with label Utah. Show all posts
Showing posts with label Utah. Show all posts

Thursday, January 25, 2018

Krombach Brand Valves for Rugged Service Conditions

metal seated butterfly valve with actuator
Metal seated butterfly valves for aggressive process
applications are a hallmark of the Krombach brand.
Image courtesy Crane CPE
The Krombach branded valves, part of the Crane CPE product offering, target challenging applications in industrial settings that benefit from the use of valves specially designed for severe service. The brand also includes a standard product offering of valves and specialties for a broad range of common industrial applications.

The Krombach line includes:

  • Butterfly Valves - High performance, resilient seated, double-eccentric, triple offset and special purpose butterfly valves.
  • Ball Valves - Process one-piece, two-piece and three-piece, metal seated, soft seated and compact ball valves.
  • Globe and Angle Valves - Bronze, cast iron, cast steel and stainless steel globe and angle valves.
  • Gate Valves - Bronze, cast iron, cast steel and stainless steel gate valves.
  • Check Valves - Ball, dual-plate, foot, full body swing, steam stop, tilting disc, wafer style swing, nozzle-type and pressure seal check valves.
  • Vacuum Relief Valves - Available with flanged or threaded connections.
  • Aerating and Deaerating Valves - Essential for trouble-free operation of pipeline systems handling liquids.
  • Float Valves - Single seated and double seated versions for a variety of applications.
  • Throttle Valves - Available with flange connection, wafer- or weld-in type.
  • Bottom Drain Valves - Available manually operated or with a diaphragm actuator.

Below is a cutsheet providing an overview of the company's standard product categories. Whatever your fluid control application, share your challenges with the valve specialists at MSEC. Leverage your own process knowledge and experience with their product application expertise to develop effective valve and automation solutions.


Thursday, January 18, 2018

Corrosion Resistant Cooling Towers

corrosion resistant HDPE cooling tower
One variant of corrosion resistant cooling tower
Image courtesy Delta Cooling Towers
Cooling towers rank highly as included components of heat rejection systems. Building and facility HVAC and industrial process cooling commonly rely on cooling towers as the final phase of transferring heat from inside a system, such as a building, to the outdoor environment. With most relying on the evaporation of water as the means to efficiently move large amounts of heat, cooling towers contain large wetted surfaces in almost continuous contact with solutions of water and various chemicals used to maintain certain fluid conditions. The heat transfer solutions can be aggressive, and many towers are constructed using metal for the wetted parts and case of the unit. This has traditionally been an area of concern with cooling tower ownership, since the combined elements of water, treatment chemicals, and time take their inevitable toll on the equipment.

Avoiding the deterioration of metal clad cooling towers is construction utilizing high-density polyethylene (HDPE). HDPE is not impacted by water, treatment chemicals, or elements often present in the air, whether harsh chemical vapors emitted from nearby industrial plants or natural corrosives such as salt air.

Delta Cooling Towers, Inc., based in New Jersey, USA, manufactures HDPE cooling towers and possesses an extensive portfolio of completed successful applications utilizing HDPE construction features. Below is a short case study showing how one industrial user benefited from installing HDPE cooling towers.

Read the case study and get more information from an application specialist. See how incorporating HDPE cooling towers into your operation can reduce maintenance burden and lead to longer machinery life.

In any business venture or other organization, relying on doing things the way they have always been done can be detrimental to real progress and improvement. Incorporating change involves risk, but good planning and careful analysis will increase the probability of success.


Friday, January 5, 2018

Piston Isolation Valves For Steam and Condensate

carbon steel or stainless steel piston valve for steam or condensate
Simple and reliable piston isolation valve is well suited
for steam and condensate applications.
Image courtesy Spirax Sarco
Piston valves are serviceable and reliable valves that are well applied to isolation use in steam and condensate systems. Recently, Spirax Sarco, globally recognized manfacturer of steam system componentry, introduced their PV4 and PV6 lines of piston isolation valves targeted at steam and condensate applications.

The new valves are available with carbon steel or stainless steel bodies, with the internals of both being stainless steel. Screwed, socket weld and butt weld connections are available in 1/2" through 2" sizes. The operation is unidirectional, so installation must have the system flow according to the arrow on the body. The only other installation restriction is that the handwheel should be above the valve body.

Accommodated pressure and temperature ranges for the PV4 and PV6 will be suitable for a broad range of steam and condensate applications. Share your steam system challenges of all types with application specialists. Leverage your own knowledge and experience with their product application expertise to develop effective solutions.


Thursday, December 21, 2017

Capsule Steam Traps

cutaway view capsule steam trap
Capsule type steam trap, cutaway view
Image courtesy Tunstall Corporation
Steam traps are an important part of a closed steam system, directing condensate on a path back to the boiler for reuse and venting non-condensing gases from the system. Of the several different types of steam traps utilized commercially, the thermostatic steam trap is but one. Thermostatic traps are often applied when the application can benefit from a utilization of some of the heat remaining in the condensate. This trap design will hold the condensate in place until it cools sufficiently below the saturation temperature of the steam.

Capsules utilized in thermostatic steam traps contain the controlling elements of the device. The parts are somewhat subject to wear through their movement, but more so from the corrosive effects of system fluid, impurities, and mechanical shock from water hammer. Tunstall Corporation specializes in the manufacture of replacement capsules for thermostatic steam traps that provide better service and extended warranty duration. Their sealed units are fabricated of stainless steel and welded to seal out deterioration due to exposure to steam and condensate. Drop in replacement capsules are available for conceivably every trap manufactured in the previous few decades.

Share your steam system requirements and challenges with application specialists, leveraging your own knowledge and experience with their product application expertise to develop an effective solution.

Wednesday, December 13, 2017

Process Tuning

sliding gate industrial process control valve
This sliding gate industrial control valve could operate
under the command of a tuned process control loop.
Image courtesy Schubert & Salzer
Controller tuning is a process whereby a controlling device in a process has a response characterized to the needs of maintaining a process condition within certain limits under a range of varying disturbances to the process. Established guidelines for automation standards exist so that every process control operator can experience the same standard of safety and maintenance in a way universally understandable. The International Society of Automation (ISA) promotes different tuning standards based on the particulars of the control process, such as temperature or liquid level control.

Liquid-level control loops are usually considered non-self-regulating processes. They require external moderation to remain uniform and for errors to either be mitigated or corrected. General rules which exist for adjusting and tuning loops for self-regulating process, such as temperature control, are often inapplicable to liquid level loops, making liquid level control loops somewhat unique in their tuning.

In order to address the counter intuitive nature of these process loops, start with a model of the loop’s ideal functionality. This can serve as a reference. After doing so, incorporate potential variables into the ideal loop and evaluate their impact on the model process. Checking equipment, then modeling the process dynamics, allows engineers to observe the manner in which the process reacts in relation to the target or goal performance.

Whereas other loops can be tuned via trial and error, liquid-level control loops should not be due to the nature of their reactions to controller input being different than that of other processes. Instead, the parameters for the control loop need to be carefully engineered, rather than specifically tuned. Liquid level loops are integrating processes, rather than self-regulating. A self-regulating process will, with no disturbances to the variables, reach an equilibrium at which the process value remains constant. Consider a non-self-regulating liquid level control loop where the fill valve is open. No equilibrium point will be achieved, just overflow. The distinction between the two types is key to understanding why tuning liquid level loops is a different process than self-regulating control loops.

Temperature and thermal loops, depending upon the process dynamics, present varying degrees of tuning challenge. PID temperature controllers are employed to adjust the heat input to a process to affect a change in, or maintenance of, a process temperature setpoint. Without proper tuning, the controller output and the resulting process performance can oscillate or be slow to respond, with a negative impact on process performance or yield. Many PID controllers have an auto-tune feature, some of which are more effective than others. The best results achievable by PID controller tuning are accomplished by defining a setpoint prior to the auto-tune process and starting the tuning procedure from a stable process condition. Tuning the controller in the same process environment in which it will operate can also be very helpful.

Share your process measurement and control challenges with experienced application specialists, combining your own knowledge and experience with their product application expertise to develop effective solutions.

Thursday, December 7, 2017

Compressed Air as a Motive Force

coalescing filters for compressed air
Coalescing filters are common components of a compressed
air system.
Image courtesy SPX Pneumatic Products
Compressed air is utilized throughout every industry and many commercial settings. While primarily used as a motive force, compressed air serves as a utility in many applications in the oil and gas, chemical and petrochemical, nuclear power, food, pharmaceutical, and automotive industries. The presence and use of compressed air across multiple industries is so essential, its importance is comparable to utilities like electricity, gas, and water.

In the control of fluid processes, compresses air facilitates operation and control of valves and other instruments. Dry air, with a sufficiently depressed dew point, can ensure process materials and equipment stay free of moisture and its associated impediments to smooth operation. The use of compressed air as either a motive force or a utility imparts minimum requirements on its quality or constituents. Confounding substances, such as particulates, water, and oil, may be entrained or contained in a compressed air stream. Various methods of filtration and moisture removal may be necessary to condition or process the compressed air in order to deliver consistent quality.

The advantages of using compressed air as a motive force in industrial settings are more numerous than appropriate for listing here, but consider that tools driven by compressed air can be more compact, lower weight and less prone to overheating than electrically driven tools. Air driven devices tend to have reduced parts count and require little maintenance, whether tools, valve actuators, pistons, or other machines. Compressed air driven devices can be fashioned to amplify the power of an electrical signal, enabling a simpler means of powering some types of loads. Compressed air, by its nature, presents no electrical hazards to the workplace.

Whenever air driven devices are utilized, attention must be given to compressed air production. The pressure, maximum flow rate demand, and compressed air quality must meet the process or operation requirements. Share your compressed air system challenges with specialists, leveraging your own knowledge and experience with their product application expertise to develop effective solutions.

Tuesday, November 28, 2017

Pipeline Cyber Security

binary stream representing industrial process control network data transfer and cyber security threat
Cybersecurity is a process control challenge that consistently evolves as new technologies come into use and new threats emerge. Since process control methods are constantly developing, the protective measures need to match the rate of change to ensure adequate levels of protection are in place. Pipelines used in the oil and gas industry, as well as in the transportation of a multitude of liquid and gaseous products, account for more than 2.3 million miles of process piping in the United States.  Natural gas pipelines are commonly monitored and controlled by, for example, programmable logic controllers or other microprocessor and communications based systems, responsible for flow regulation and various process conditions. Because of the prevalence of these systems, they are a target of increasing attacks, on both PLCs and other SCADA related devices, such as compressors, remote terminal units, communication networks, and other critical process infrastructure elements.

While developments in technology have provided operating advantages and improvements to the process industries, the more complex and advanced the systems may also increase the exposure to malicious penetration and mischief by unauthorized parties (hackers). Because of this, diligence by industry professionals, while always a strong component of protecting against outside threats, has been augmented via new guidelines meant to better prepare all process operators against more coordinated cyber-attacks.

Basic preventative measures, such as a firewall, are no longer a sufficient bulwark against the increasing threats. Instead, the entire process must be evaluated and monitored so that each individual piece of the network is understood fully. If a part of the system starts behaving in an abnormal way, then an understanding of what that specific PLC or component affects must be immediately known. The most effective protective programs will be able to function without needing any downtime, and will also be able to learn the network easily. Whenever the defense program gets triggered, it needs to not only provide a general alert to the process operator, but must also be able to provide context so that the previous knowledge of how the system works can be applied to mitigate the current problem.

Currently, the oil and gas industry has transitioned to what is being termed a ‘holistic’ approach to cyber defense. In order for the best security possible to be employed, the human element of process control must function in tandem with the autonomous programs. The human component of process operation, where it exists, can be unpredictable and present vulnerabilities that may not be known or anticipated. Everything must be considered.

Industrial process operation involves many areas of risk, with cyber attack being just one. The right kind of planning and response to risk can mitigate the potential impact. Security efforts, technology, and knowledge must keep pace with threats which emerge to process pipeline security. Mountain States Engineering and Controls participates in the oil and gas industry throughout the western U.S.

Thursday, November 16, 2017

Forced Draft Cooling Tower With 20 Year Warranty

corrosion resistant HDPE cooling tower rated 50 tons with forced draft
Forced draft corrosion resistant cooling tower
with forced draft, rated 50 tons. Pioneer series.
Image courtesy Delta Cooling Towers
Delta Cooling Towers specializes in the design and construction of corrosion resistant cooling towers and similar equipment. Much of the tower construction is HDPE or other non-metallic material, enabling the company to offer a 20 year warranty on their equipment.

Cooling towers are employed worldwide in HVAC applications and process fluid cooling. In addition to their industry leading corrosion resistance, Delta Cooling Towers also offers anti-microbial protection which combats the growth of microbes responsible for Legionnaires Disease and other respiratory ailments. The various product lines cover heat transfer capacities to accommodate any installation.

There is a lexicon employed in the description of cooling tower performance and operation. Some commonly used terms, along with their meaning, is provided below. The terms and their meanings is pulled from the owner's manual provided by Delta Cooling Towers for their Pioneer series of forced draft cooling towers.

Share your process and HVAC cooling challenges with application experts, leveraging your own knowledge and experience with their product application expertise to develop an effective solution.

Cooling Tower Terms and Definitions

  • BTU - A BTU is the heat energy required to raise the temperature of one pound of water one degree Fahrenheit in the range from 32° F. to 212° F.
  • Cooling Range - The difference in temperature between the hot water entering the tower and the cold water leaving the tower is the cooling range.
  • Approach - The difference between the temperature of the cold water leaving the tower and the wet-bulb temperature of the air is known as the approach. The approach fixes the operating temperature of the tower and is a most important parameter in determining both tower size and cost.
  • Drift - The water entrained in the air flow and discharged to the atmosphere. Drift loss does not include water lost by evaporation. Proper tower design and operation can minimize drift loss.
  • Heat Load - The amount of heat to be removed from the circulating water through the tower. Heat load is equal to water circulation rate (gpm) times the cooling range times 500 and is expressed in BTU/hr. Heat load is also an important parameter in determining tower size and cost.
  • Ton - An evaporative cooling ton is 15,000 BTU's per hour.
  • Wet-Bulb Temperature - The lowest temperature that water theoretically can reach by evaporation. Wet-Bulb Temperature is an extremely important parameter in tower selection and design and should be measured by a psychrometer.
  • Pumping Head - The pressure required to pump the water from the tower basin, through the entire system and return to the top of the tower.
  • Make-Up - The amount of water required to replace normal losses caused by bleedoff, drift, and evaporation.
  • Bleed Off (Blowdown) - The circulating water in the tower which is discharged to waste to help keep the dissolved solids concentrating in the water below a maximum allowable limit. As a result of evaporation, dissolved solids concentration will continually increase unless reduced by bleed off.

Thursday, October 26, 2017

When to Use a Globe Valve for Fluid Process Control

cast iron globe valves
Cast iron globe valves are utilized extensively in steam,
HVAC, and other commercial and industrial applications
Image courtesy of Crane Co.
Industrial process control often involves the regulation of fluid flow. There are almost uncountable types and variants of flow control valves, each with a particular set of attributes that can make it the advantageous choice an application.

When the process calls for controlling flow over a range of possible values, known as throttling, a globe valve may be a good candidate for the application.

Globe valves are characterized by the change in direction of fluid flow as it passes through the valve and around the plug positioned in an opening through which fluid must pass. The plug is connected to a stem extending to the exterior of the valve body through the bonnet. Movement of the stem will reposition the plug in relation to the opening, providing a successively larger or smaller opening area through which fluid can pass.

Globe valves are available in tee, angle, and wye configurations, as well as an enormous range of special configurations to suit specific applications.
simplified globe valve diagram
Simplified globe valve diagram
Image courtesy Wikipedia


What are some potential advantages of globe valves?
  • Good throttling and shutoff capability
  • Comparatively easy maintenance
  • Comparatively short travel of plug from open to closed position
  • Seats can usually be resurfaced when worn
What are some limiting factors for globe valves?
  • Higher valve pressure drop than some other designs
  • No straight through fluid path
  • Potentially higher actuator torque requirements than other valve types
  • Seal area is unprotected from exposure to process fluid flow
When flow throttling capability is the overriding concern for an application, a globe valve is a good candidate for consideration. Share your flow control challenges with valve and automation specialists. Combining your process knowledge and experience with their product application expertise will produce effective solutions.

Wednesday, August 23, 2017

Cooling Towers: Operating Principles and Systems

evaporative cooling tower made of HDPE plastic
Example of evaporative cooling tower, fabricated
from HDPE plastic to resist corrosion.
Image courtesy Delta Cooling Towers
The huge, perfectly shaped cylindrical towers stand tall amidst a landscape, with vapor billowing from their spherical, open tops into the blue sky. Such an image usually provokes a thought related to nuclear power or a mysterious energy inaccessible to the millions of people who drive by power plants every day. In reality, cooling towers – whether the hyperboloid structures most often associated with the aforementioned nuclear power plants or their less elegantly shaped cousins – are essential, process oriented tools that serve as the final step in removing heat from a process or facility. The cooling towers at power plants serve as both an adjuster of a control variable essential to the process and also as a fascinating component of the process behind power creation. The importance and applicability of cooling towers is extensive, making them fundamentally useful for industrial operations in power generation, oil refining, petrochemical plants, commercial/industrial HVAC, and process cooling.

In principle, an evaporative cooling tower involves the movement of a fluid, usually water with some added chemicals, through a series of parts or sections to eventually result in the reduction of its heat content and temperature. Liquid heated by the process operation is pumped through pipes to reach the tower, and then gets sprayed through nozzles or other distribution means onto the ‘fill’ of the tower, reducing the velocity of the liquid to increase the fluid dwell time in the fill area. The fill area is designed to maximize the liquid surface area, increasing contact between water and air. Electric motor driven fans force air into the tower and across the fill area. As air passes across the liquid surface, a portion of the water evaporates, transferring heat from the water to the air and reducing in the water temperature. The cooled water is then collected and pumped back to the process-related equipment allowing for the cycle to repeat. The process and associated dispersion of heat allows for the cooling tower to be classified as a heat rejection device, transferring waste heat from the process or operation to the atmosphere.

Evaporative cooling towers rely on outdoor air conditions being such that evaporation will occur at a rate sufficient to transfer the excess heat contained in the water solution. Analysis of the range of outdoor air conditions at the installation site is necessary to assure proper operation of the cooling tower throughout the year. Evaporative cooling towers are of an open loop design, with the fluid exposed to air.

A closed loop cooling tower, sometimes referred to as a fluid cooler, does not directly expose the heat transfer fluid to the air. The heat exchanger can take many forms, but a finned coil is common. A closed loop system will generally be less efficient that an open loop design because only sensible heat is recovered from the fluid in the closed loop system. A closed loop fluid cooler can be advantageous for smaller heat loads, or in facilities without sufficient technical staff to monitor or maintain operation of an evaporative cooling tower.

Thanks to their range of applications, cooling towers vary in size from the monolithic structures utilized by power plants to small rooftop units. Removing the heat from the water used in cooling systems allows for the recycling of the heat transfer fluid back to the process or equipment that is generating heat. This cycle of heat transfer enables heat generating processes to remain stable and secure. The cooling provided by an evaporative tower allows for the amount of supply water to be vastly lower than the amount which would be otherwise needed. No matter whether the cooling tower is small or large, the components of the tower must function as an integrated system to ensure both adequate performance and longevity. Understanding elements which drive performance - variable flow capability, potential HVAC ‘free cooling’, the splash type fill versus film type fill, drift eliminators, nozzles, fans, and driveshaft characteristics - is essential to the success of the cooling tower and its use in both industrial and commercial settings.

Design or selection of an evaporative cooling tower is an involved process, requiring examination and analysis of many facets. Share your heat transfer requirements and challenges with cooling tower specialists, combining your own facilities and process knowledge and experience with their application expertise to develop an effective solution.`

Friday, August 18, 2017

Thermodynamic Steam Traps

cutaway view thermodynamic steam trap
Cutaway view of disc type thermodynamic steam trap
Image courtesy of Spirax Sarco
Condensate return is an essential operation in any closed loop steam system. Steam that has lost its latent heat will collect in the piping system as hot liquid water (condensate). This liquid needs to be separated from the steam and returned to the boiler feedwater equipment without letting steam escape in the process.

Various items of steam utilization equipment and processes will result in condensate formation at different rates. The device that collects and discharges condensate to the return portion of the system is called a steam trap. There are numerous physical principals and technologies employed throughout the range of available steam trap types. Each has application limitations and strengths making them more or less suitable for a particular installation.

A thermodynamic steam trap relies on the energy provided by the condensate to move a disc which controls the flow of the condensate into the return system. The disc is the only moving part in the device. Condensate flows through a port to a chamber on the underside of the disc, lifting the disc and directing the flow to the return system or drain. Eventually, the fluid flowing into the chamber will reach a point where some of the condensate flashes to steam. A portion of this steam flows through a channel into the space above the disc, called the control chamber. The increase in pressure in the control chamber due to the steam influx pushes downward on the disc, seating it in a closed position. The trap, with the disc seated, remains in the closed position until the flash steam in the control chamber cools and condenses. Then the disc can be opened again by the inflow of condensate.

The thermodynamic disc trap is:

  • Easy to install
  • Compact
  • Resistant to damage from freezing
The single trap can cover a wide range of system pressure, and the simple construction translates into low initial cost. Properly matching any steam trap to its application is important. Share your condensate return and steam system challenges with specialists, combining your knowledge and experience with their product application expertise to develop effective solutions.



Tuesday, August 8, 2017

Orifice Plate - Primary Flow Element

orifice plate drawing
Orifice plates are simple in appearance, but exhibit
precision machining.
Image courtesy of Fabrotech Industries
An orifice plate, at its simplest, is a plate with a machined hole in it. Carefully control the size and shape of the hole, mount the plate in a fluid flow path, measure the difference in fluid pressure between the two sides of the plate, and you have a simple flow measurement setup. The primary flow element is the differential pressure across the orifice. It is the measurement from which flow rate is inferred. The differential pressure is proportional to the square of the flow rate.

An orifice plate is often mounted in a customized holder or flange union that allows removal and inspection of the plate. A holding device also facilitates replacement of a worn orifice plate or insertion of one with a different size orifice to accommodate a change in the process. While the device appears simple, much care is applied to the design and manufacture of orifice plates. The flow data obtained using an orifice plate and differential pressure depend upon well recognized characteristics of the machined opening, plate thickness, and more. With the pressure drop characteristics of the orifice fixed and known, the measuring precision for differential pressure becomes a determining factor in the accuracy of the flow measurement.

There are standards for the dimensional precision of orifice plates that address:
  • Circularity of the bore
  • Flatness
  • Parallelism of the faces
  • Edge sharpness
  • Surface condition
Orifice plates can be effectively "reshaped" by corrosion or by material deposits that may accumulate from the measured fluid. Any distortion of the plate surface or opening has the potential to induce measurable error. This being the case, flow measurement using an orifice plate is best applied with clean fluids.

Certain aspects of the mounting of the orifice plate may also have an impact on its adherence to the calibrated data for the device. Upstream and downstream pipe sections, concentric location of the orifice in the pipe, and location of the pressure measurement taps must be considered.

Properly done, an orifice plate and differential pressure flow measurement setup provides accurate and stable performance. Share your flow measurement challenges of all types with a specialist, combining your own process knowledge and experience with their product application expertise to develop an effective solution.

Thursday, August 3, 2017

Thermocompressor Breathes New Life into Low Pressure Waste Steam

steam thermocompressor
Steam Jet Thermocompressor from Spirax Sarco
mixes high pressure and low pressure steam supplies
Energy conservation and energy efficiency have contributed very large cost savings to many industrial and commercial operations over the past two decades. Projects with modest payback periods quickly begin their contributions directly to the bottom line of the balance sheet. In many instances, incorporating energy conservation and efficiency measures also improves the overall functioning of the consuming systems and equipment. In order to save energy, it is generally necessary to exercise better control over equipment or system operation by gathering more information about the current operating state. This additional information, gathered through measurement instrumentation, often finds use in other ways that improve productivity and performance.

Steam is utilized throughout many industries as a means of transferring heat, as well as a motive force. Much energy is consumed in the production of steam, so incorporating ways of recovering or utilizing the heat energy remaining in waste steam is a positive step in conservation.

A thermocompressor is a type of ejector that mixes high pressure steam with a lower pressure steam flow, creating a usable discharge steam source and conserving the latent heat remaining in the low pressure steam. The device is compact and simple, with no moving parts or special maintenance
thermocompressor labelled schematic
Schematic of basic thermocompressor, showing suction
inlet at the bottom and high pressure steam nozzle.
Image courtesy of Spirax Sarco
requirements. Two general varieties are available. The fixed nozzle style is intended for applications with minimal variation in the supply and condition of the suction steam (the low pressure steam). Some control is achievable through the regulation of the high pressure steam flow with an external control valve. A second style provides a means of regulating the cross sectional area through which the high pressure steam flows in the nozzle. This style is best applied when specific discharge flow or pressure is required, or there is significant variation in the inlet steam conditions.

Share all your steam system challenges with a steam system application specialist. Combine your own process and facilities knowledge and experience with their product application expertise to develop effective solutions.


Thursday, July 27, 2017

Valve Positioners

industrial valve actuator with positioner
Valve positioner installed on pneumatic actuator
Courtesy Crane ChemPharma Energy
Valve positioners can provide process operators with a precise degree of valve position control across the valve movement range, as well as information about valve position. A relationship exists between applied pneumatic signal pressure and the position of the valve trim. The relationship between the two elements is dependent upon the valve actuator and the force of the return spring reacting to the signal pressure. In a perfect world, the spring and pneumatic forces would reach equilibrium and the valve would return to the same position in response to an applied signal pressure. There are other forces, however, which can act upon the mechanism, meaning the expected relationship between the original two elements of pressure and position may be offset. For example, the packing of the valve stem may result in friction, or the reactive force from a valve plug resulting from differential pressure across the area of the plug may be another.

While these elements may seem minor, and in some cases they are, process control is about reducing error and delivering a desired or planned output. Inclusion of a positioner in the valve assembly can ensure that the valve will be set in accordance with the controller commands.

Each positioner functions as a self-contained small scale control system. The first variable in the positioning process is the current valve position, read by a pickup device incorporated in the positioner. A signal which is sent to the positioner from the control system, indicating the desired degree of opening, is used as the setpoint. The controller section of the positioner compares the current valve position to the setpoint and generates a signal to the valve actuator as the output of the positioning process. The process controller delivers a signal to the valve, and then the positioner takes that signal and supplies air pressure required to accomplish the needed adjustment of the stem position. The job of the valve positioner is to provide compensatory force and to act as a counterbalance against any other variables which may impact valve stem position.

Magnetic sensors can be employed to determine the position of the valve stem. The magnetic sensor works by reading the position of a magnet attached to the stem of the valve. Other technologies can be employed, and all have differing ways of overcoming degrees of inaccuracy which may arise with wear, interference, and backlash. In addition to functioning as a positioner, control valve positioning devices can also function as volume boosters, meaning they can source and subsequently ventilate high air flow rates from sources other than their pneumatic input signal (setpoint). These devices can positively affect and correct positioning and velocity of the valve stem, resulting in faster performance than a valve actuator solely reliant on a transducer.

The inclusion of a positioner in a control valve assembly can provide extended performance and functionality that deliver predictable accurate valve and process operation. Share your valve automation requirements with a knowledgeable specialist and combine your process knowledge and experience with their product application expertise to develop an effective solution.

Friday, July 21, 2017

Pressure Motive Condensate Pumps



In a closed steam system, condensate must be returned to the feedwater side of the boiler. Moving this condensate effectively through the system is essential to maintaining design performance levels throughout the system. Condensate can be considered "spent steam", but still retains great value as preheated and treated feedwater for the boiler.

Three general methods are employed to transport condensate from where it is collected to where it is reused. If the facility layout permits, gravity can be the motive force to move the condensate back to the boiler. A second option is a mechanical pump, unsurprisingly called a condensate pump. The third common option is to employ system steam pressure to drive the condensate through the return piping and back to the boiler.

The concept of gravity return for the condensate is easy to envision....liquid flows downhill. Mechanical pumps, as well, are a well understood means of moving liquids. When the condensate collector reaches a certain fill level, the pump is energized and the liquid is forced through the return piping.

Using pressure as the motive force for condensate return involves coordinated operation of inlet, outlet, and vent openings to the condensate collection vessel. A float inside the collection vessel and a connected mechanism provide control of the valves at the vessel openings. In the video, you can see how the valve operating sequence provides for periods of condensate collection, then condensate discharge.

Share all of your steam system challenges with application specialists, combining your own process and facilities knowledge and experience with their product application expertise to develop effective solutions.

Wednesday, July 19, 2017

Integrated Solution for Chilled Water Coil Control

integrated sensors, controller, control valve, actuator for HVAC
Monitrol includes controller, sensors, control valve, and
actuator in a single integrated package.
Image courtesy of Warren Controls
The final control element used for heating or cooling via a heat transfer fluid is going to be a control valve, most often one capable of modulating the fluid flow by precise valve positioning. This control activity requires sensors, the control valve, a controller, and an actuator.

Selecting, installing, and coordinating the operation of these components can be challenging and time consuming, especially when the components are sourced from varied manufacturers. Warren Controls delivers a consolidated solution with their Monitrol line of control valves intended for heat transfer control tasks and related operations. The Monitrol concept involves combining pre-engineered and matched controllers and actuators with flow control valves equipped with built-in sensors for pressure, temperature, or flow. Measurement and control is performed locally, with communications between the local and central controllers exchanging setpoint and performance information. The solution is compact and simplified, enabling easy selection, installation, and startup.

More details are provided in the document included below. There are numerous product variants to accommodate a wide array of field applications. Share your fluid control and heat transfer requirements and challenges with an application expert, combining your own facility and process knowledge with their product application expertise to develop an effective solution.


Thursday, July 6, 2017

Added Safety For Pneumatic Actuators

pneumatic actuator for industrial process control valve
XL Series Pneumatic Actuator
Courtesy Emerson - Hytork
Manufacturers of industrial process control gear keep the safety of their customers as a high priority item when designing products. There is much at stake in industrial operations, so every instance where the probability or impact of failure can be reduced is beneficial.

Pneumatic valve actuators utilize pressurized air or gas as the motive force to position a valve. A common version of these air powered actuators employs a rack and pinion gear set that converts the linear movement of air or spring driven pistons to rotational movement on the valve shaft. When one side of the piston is pressurized, the pinion bearing turns in one direction. When the air or gas from the pressurized side is vented, a spring (spring-return actuators) may be used to rotate the pinion gear in the opposite direction. A “double acting” actuator does not use springs, instead using the pneumatic supply on the opposing side of the piston to turn the pinion gear in the opposite direction.

From time to time, service or maintenance operations for the actuator may require opening of the pressure containing case. This is a potentially hazardous step and confirmation that the case is not pressurized when disassembly is undertaken is essential to a safe procedure. Many pneumatic actuators have cases assembled with numerous threaded fasteners. Hytork, an Emerson brand, employs a keyway and flexible stainless steel key to affix the end caps to their XL Series pneumatic actuators. This method provides a number of benefits, not the least of which is preventing the removal of the key and end cap if the case is pressurized.

Find out more about the XL Pneumatic Actuators in the illustrated piece provided below. Share your industrial fluid control challenges with industrial valve and automation specialists, combining your own process experience and knowledge with their product application expertise to develop effective solutions.


Thursday, June 29, 2017

Sterling Condensate Return and Steam Control Equipment



Sterling, under the Sterlco brand, manufactures a range of Steam control products for commercial and industrial use. Steam traps, condensate return pumps, boiler feed pumps, and self regulating temperature control valves are all part of the product offering. The video included with this posting provides a short overview of the product extent of the Sterlco line.

Share your steam system challenges with product application specialists. Combine your own facilities and process knowledge and experience with their product application expertise to develop the  most effective solutions.

Tuesday, June 20, 2017

Shell and Tube Heat Exchangers

large shell and tube heat exchangers at oil refinery
These shell and tube heat exchangers are at an oil refinery, but
their application crosses all industry boundaries.
Cars are something which exist as part of the backbone of modern society, for both personal and professional use. Automobiles, while being everyday objects, also contain systems which need to be constantly maintained and in-sequence to ensure the safety of both the machine and the driver. One of the most essential elements of car ownership is the understanding of how heat and temperature can impact a car’s operation. Likewise, regulating temperature in industrial operations, which is akin to controlling heat, is a key process control variable relating to both product excellence and operator safety. Since temperature is a fundamental aspect of both industrial and consumer life, heat management must be accurate, consistent, and predictable.

A common design of heat exchangers used in the oil refining and chemical processing industries is the shell and tube heat exchanger. A pressure vessel, the shell, contains a bundle of tubes. One fluid flows within the tubes while another floods the shell and contacts the outer tube surface. Heat energy conducts through the tube wall from the warmer to the cooler substance, completing the transfer of heat between the two distinct substances. These fluids can either be liquids or gases. If a large heat transfer area is utilized, consisting of greater tube surface area, many tubes or circuits of tubes can be used concurrently in order to maximize the transfer of heat. There are many considerations to take into account in regards to the design of shell and tube heat exchangers, such as tube diameter, circuiting of the tubes, tube wall thickness, shell and tube operating pressure requirements, and more. In parallel fashion to a process control system, every decision made in reference to designing and practically applying the correct heat exchanger depends on the factors present in both the materials being regulated and the industrial purpose for which the exchanger is going to be used.

The industrial and commercial applications of shell and tube heat exchangers are vast, ranging from small to very large capacities. They can serve as condensers, evaporators, heaters, or coolers. You will find them throughout almost every industry, and as a part of many large HVAC systems. Shell and tube heat exchangers, specifically, find applicability in many sub-industries related to food and beverage: brewery processes, juice, sauce, soup, syrup, oils, sugar, and others. Pure steam for WFI production is an application where special materials, like stainless steel, are employed for shell and tube units that transfer heat while maintaining isolation and purity of a highly controlled process fluid.

Shell and tube heat exchangers are rugged, efficient, and require little attention other than periodic inspection. Proper unit specification, selection, and installation contribute to longevity and solid performance. Share your project challenges with application experts, combining your own process and facilities knowledge with their product application expertise to develop effective solutions.

Thursday, June 15, 2017

Natural Gas Fueling Station Process Filter and Dryer

natural gas vehicle fueling station dryer with stationary regenerator
Single tower natural gas dryer with stationary regeneration system
used for removing water vapor and particulate contaminants from
vehicle fuel.
Courtesy SPX Flow - Pneumatic Products
Natural gas fueled vehicles now occupy a formidable niche in the transportation market. With low cost, low emission operation, natural gas vehicles continue to expand their presence in fleets around the world.

Commercially available engines of almost all types operate best and longest when powered with clean fuel that is free of particulates and other contaminants that increase wear on internal and moving parts. Water vapor also has some deleterious effects on many components and should be kept at very low levels.

Fuel can change custody and container numerous times during transport from production to consumption point. Opportunities for contamination exist along the supply chain, making a final processing of the fuel immediately prior to its dispensing to a vehicle a positive and beneficial operation.

SPX Flow, under the Pneumatic Products brand, manufactures single and twin tower desiccant dryers designed to remove water vapor from natural gas. The skid mounted units also include particulate and coalescing filters that capture solid contaminants to a submicron level.

Specifically engineered for large flow heavy-duty natural gas vehicle fleet refueling applications, units are available for intermittent, low, moderate, and heavy demand operations. Single tower units are economical for low to moderate levels of use. Twin tower systems, with self-contained regeneration, provide continuous operation and delivery of dried compressed natural gas (CNG) for fueling operations.

Single tower dryers can be provided with a stationary desiccant regeneration system on board. This enhances convenience by eliminating the need for a third party regeneration service. The desiccant is processed in place, without replacement. Single tower dryers are suitable for low to moderate volume application.

Single tower units, without a stationary regeneration system, are suitable for intermittent or low volume use. A mobile regeneration unit can provide self directed processing of the desiccant media in place, eliminating the need for disposal and replacement. Alternatively, third party service providers can come to the site and replace or regenerate the desiccant.

Twin tower purification systems are completely self-contained, fully automatic, heat-reactivated, closed-loop blower purge units capable of continuous operation for facilities with high flow requirements or uninterrupted 24 hour operation.

More detail is provided in the datasheet below. Share your natural gas vehicle fueling station challenges with a product application specialist for help in determining the most suitable equipment for your application.