Showing posts with label Idaho. Show all posts
Showing posts with label Idaho. Show all posts

Monday, October 22, 2018

Emerson/Kunkle Pressure Relief Valves: Operating and Safety Instructions

Kunkle Pressure Relief Valve
Emerson/Kunkle Pressure Relief Valve
Before installation these instructions must be fully read and understood.

PRE-INSTALLATION HANDLING

This pressure relief valve is designed to protect equipment from overpressure. The valve should be handled with care, not subjected to heavy shock loads, and protected to prevent dirt from getting inside. It should be installed correctly. Failure to do so could result in property damage or serious injury to personnel. When hoisting the valve into position for installation, care should be exercised so that lifting straps do not contact the valve lift lever. service life may vary upon condition of service. Check unit at least once per 8000 hours or longer intervals based upon site experience.

INSTALLATION
  1. Mount the valve in a vertical position so that the valve body is self draining. If a body drain port is provided, make sure it is open when required by the ASME code. Do not plug any bonnet vent openings. The inlet piping should be as short as possible, with no elbows, and equal to or greater than the size of the pressure relief valve inlet connection. This will help to limit the inlet pressure drop to 3% or less when the valve is relieving.
  2. When discharge piping is connected to valve outlet, make sure it is self draining if a body drain port is not used. The valve should not be connected to any discharge pipe that contains pressure before the valve opens or to any pipe where the pressure build-up is greater than 10% of the set pressure when the valve is open and relieving.
    Discharge piping, other than a short tailpipe, must be supported. For steam service, a drip pan elbow or flexible connection between the valve and the pipe should be used to prevent excessive pipe stress, due to thermal expansion, from being imposed on the valve body.
  3. For threaded valves, to prevent sealing compound from entering and damaging the valve, apply a small amount of pipe thread sealing compound to external threads only. Do not put any sealing compound on the first thread or on any internal threads. To do so may cause the sealing compound to enter the valve and cause seat leakage. Do not use the valve body or bonnet for installing the valve in threaded connections. Use the wrench flats provided to tighten the valve to the connecting pipe, and do not over-tighten. To do so may cause valve leakage.
  4. For flanged valves, use new gaskets and tighten the mounting studs evenly.
OPERATION
  1. Maintain a system operating pressure at least 5 psig or 10% below the set pressure of the valve, whichever is greater.  Operating too close to the valve set pressure will cause seat leakage and will shorten the time between valve maintenance.
  2. Do not use the safety valve as a control valve to regulate system operating pressure. Excessive operation will cause the seat to leak and will require more frequent valve maintenance.
  3. ASME Section I and VIII valves equipped with lift levers are designed to be operated only when the system pressure is 75% of set pressure or greater. ASME Section IV valves may be operated at any set pressure. When hand operating the valve, hold it open long enough to purge any foreign matter from the seat area. If a cable or wire is attached to the lift lever for remote actuation, make sure the direction of pull is the same as it would be if the lever were pulled directly by hand.
MAINTENANCE

Maintenance should be performed on a regular basis. An initial inspection interval of 12 months is recommended. Depending on the service conditions and the condition of the valve, the inspection interval may be decreased or increased. Use only Kunkle parts for repair. Depending o the local jurisdictional requirements where the valve is installed, repairs may have to be made by a repair facility holding a VR stamp.

WARNING

Removal of the seal wire or any attempt to adjust, repair, or modify this product by non-qualified or non-authorized persons voids the product guarantee and may cause serious damage to equipment, personal injury, and death. Kunkle Valve is not liable for any damages resulting from misuse or misapplication of its products.

Wednesday, September 19, 2018

What is an Industrial Gate Valve?

Industrial valves
Industrial valves come in a wide variety of types and styles.
 (Image courtesy of Crane)
Industrial valves are used for flow control in industrial processes at specific locations in a piping system. Valves start, stop, throttle, or divert the process fluid flow. Valve application characteristics are diverse, resulting in a broad array of possible valve choices. Valve styles and types have evolved based on their performance, safety, effectiveness, and longevity.

Valve type generally refers to the means employed to control fluid flow, specifically the body style and orifice design. These valve characteristics are used to determine whether a valve type may be suitable for your process application. The most common valve types include gate and globe valves (referred to as linear valves) and ball, plug, and butterfly valves (referred to as quarter-turn valves). All these types of valves have numerous variations and customizations occurring within each type.

The Gate Valve

Gate valve diagram
Gate valve diagram.

Gate valves utilize a movable wedge, often round or rectangular, that is positioned as to restrict the process flow path. This wedge, referred to as the gate or disc, is connected to a valve stem which extends to the exterior of the valve body. Linear motion of the stem will position the gate within the valve body to provide some degree of obstruction to the process flow path. Fully inserting the gate into the media path will shut off the flow, while successively withdrawing the gate will increase the opening through which fluid can pass and allows for increasing flow rates. Seals are provided along the planar surfaces where the gate contacts the valve body.

Gate Valve Advantages
  • When fully open, these valves provide little or no restriction to fluid flow. 
  • This valve type provides a straight through passage.
  • Gate valves can be employed bi-directionally, with flow control effectively available in both directions.
  • Installation space dimensions along the flow path are minimal.
  • Because the gate movement is perpendicular to the flow direction, the energy required to move the gate is generally low, allowing smaller actuators.
  • Closure of gate valves is comparatively slow to other types of valves, reducing the physical shock (hammering) in the piping system.
Additional Gate Valve Application Considerations
  • Valve seals are exposed to the fluid flow as the gate opens. The effects of the process media velocity and media corrosiveness on the seal material may cause deterioration at an unacceptable pace, particularly in throttling applications.
  • Gate valve stems generally extend substantially from the valve body, as they must accommodate the mounting of any required actuator and the entire range of motion of the gate. Some installations may not be able to provide the needed space for this arrangement.
  • The slower speed at which gate valves open and close may not be suitable for some applications.
  • Gate valves are generally not recommended for throttling the process flow, and using them in control applications could  result in gate vibration. There is also concern about expedited seal wear due to the exposure to higher process media velocities while throttling.

Friday, August 31, 2018

What is a Cooling Tower?

An evaporative cooling tower is heat removal device that uses ordinary water to transfer process waste heat from building and equipment into the atmosphere. All cooling towers operate on the principle of removing heat from water by evaporating a small portion of water that is recirculated through the unit.

The mixing of warm water and cooler air releases latent heat of vaporization, causing a cooling effect to the water.  Cooling towers are a key component of many refrigeration systems and can be found in industries such as chemical processing plants, power plants, steel mills, food processing plants, and many other manufacturing companies where process cooling is required.  Cooling towers are also used to provide comfort cooling for large commercial buildings such as universities, government facilities, airports, schools, hospitals, and hotels.

The video below provides a short review of what cooling towers are and why they are important.

Tuesday, August 14, 2018

Industrial Control Valve Basics

Understanding industrial control valve design and operation is very important if you work as a process engineer, a plant maintenance person, or if you design process control loops. Control valves are used extensively in power plants, pulp and paper mills, chemical manufacturing, petro-chemical processing, mining facilities, HVAC and steam distribution systems.

There are many types, manufacturers, body styles, and specialized features, but the they all share some basics operating principles. The video below explains components, operation, and fundamentals of how control valves operate.

https://mnteng.com
303-232-4100

Monday, July 23, 2018

Introducing VSI Controls Control Valves

VSI Controls
VSI Controls™, a newly-formed control valve company and wholly-owned subsidiary of PetrolValves™, offers Customers an exciting alternative to procure general and severe service rotary and reciprocating control valve systems that provide a best-fit solution for their processes.

VSI Controls™ combines the products and technology of Valtek Sulamericana™ - a leading control valves system manufacturer with 35 years’ experience supplying severe service solutions - with the financial strength, global infrastructure and manufacturing and technical prowess of PetrolValves™.

Company Strengths
  • A long history of technology and innovation originating from Valtek Sulamericana™. 
  • The financial strength and global infrastructure of PetrolValves™ 
  • A highly experienced and skilled technical team of control valve experts
Their product offering can be reviewed in the embedded document below, or you can download a PDF of the VSI Controls Control Valve Catalog here.

For more information, contact Mountain States Engineering & Controls by visiting https://mnteng.com or calling 303-232-4100.


Monday, July 16, 2018

Hazardous Area Adjustable Pressure Switch with Turck® Connector Eliminates Need for Junction Box

CCS Series 6900GE* and 6900GZE*Custom Control Sensors (CCS) is a manufacturer of pressure, temperature and liquid flow switches and sensors for the aerospace, defense, industrial and energy markets. They have a new pressure switch design with an integrated Turck® electrical connection that provides an outstanding seal and eliminates the need for a junction box.

CCS Series 6900GE* and 6900GZE*

The Turck® electrical connection provides easy “plug and play” in Class I, Division 2 applications and superior ingress protection.
  • No electrical junction box required.
  • Highly reliable devices utilizing the CCS Dual-Snap® Belleville disc spring principle pioneered by CCS’ engineers.
  • Engineering based on aerospace technology.
  • Rigid, compact and internally adjustable for convenient field set point adjustment.
  • Repeatable and stable set points.
  • Vibration and shock resistant.
  • High cycle life.
  • High over-pressure capability. (System and Proof)
  • Hermetically sealed electrical assembly for environmental protection.
Adjustable set point range:
1 to 3400 PSIG 0.07 to 234 bar 6.89 to 23400 kPa

Operating temperature: Temperature limits change with O-ring selection. -40° to 176°F (-40° to 80°C)

Standard features:
  • CE Mark
  • CRN
  • Dual Seal: ANSI/ISA-12.27.01
  • NACE MR0175 / ISO 15156
  • NEMA: 4, 7, 9,13 / IP66
  • U.L. / cUL
  • Hermetically Sealed Electrical Assembly
  • 316 SST Electrical Assembly
For more information, contact Mountain States Engineering & Controls by visiting https://mnteng.com or by calling 303-232-4100.

Thursday, June 14, 2018

Mountain States Engineering and Controls Products

Mountain States Engineering and Controls represents some of the most recognized and innovative manufacturers in the market today. In some relationships with our manufacturers, Mountain States Engineering and Controls acts as a representative, and with others as a distributor. Depending on the complexity of the application or the product, some material is sold exclusively on a direct basis, where other products are made available through authorized stocking distributors or select wholesalers.

Mountain States Engineering and Controls' products solve challenging problems for industrial and commercial applications in the power, chemical, mining, energy, water treatment, and manufacturing industries as well as in universities, hospitals, and government facilities.

https://mnteng.com
303-232-4100

Tuesday, May 22, 2018

Design of Fluid Systems - Steam Utilization Handbook

Steam Utilization
Recognizing the on-going need for education as it relates to the fundamentals of steam including the most efficient use of its heat content, Spirax Sarco has developed the following handbook on steam ulilization.

This handbook represents over 100 years of steam experience in the proper selection, sizing and application of steam traps, pressure and temperature controls, and condensate recovery systems in major industrial plants throughout the world.

You can review the embedded document below, or you can download your own copy of the "Design of Fluid Systems - Steam Utilization Handbook" here.

Monday, April 30, 2018

Lined and Sleeved Valves Used in Mining Operations

FluoroSeal® Non-Lubricated Plug Valves
Flouroseal Plug Valve
Mining applications can be hard on the equipment. Abrasive, corrosive, erosive — all those conditions apply in varying proportions. FluoroSeal® Non-Lubricated Plug Valves, both Sleeved and Lined, can handle even the hardest of condition combinations, in a variety of mining operations:
  1. Alumina Refineries 
  2. Bauxite
  3. Carbon Strips
  4. Copper
  5. Cyanide
  6. Gold
  7. Lime Slurry
  8. Nickel
  9. Phosphoric Acid
  10. Sulfuric Acid
Read the application note below, or download the Lined & Sleeved Valves for Mining PDF here.

Thursday, April 19, 2018

Mountain States Engineering & Controls

Mountain States Engineering & Controls is a Manufacturer's Representative & Distributor of process equipment and controls headquartered in Lakewood, Colorado since 1978. We serve the markets of Colorado, New Mexico, Wyoming, Montana, Utah, Nevada, Idaho, and the western Dakotas.

https://mnteng.com
303-232-4100

Wednesday, March 7, 2018

Combining Rupture Discs With Pressure Relief Valves

pressure safety valve
A safety valve protects closed systems from excessive pressure
Image courtesy Kunkle Valve Division - Pentair
Safety and pressure relief valves are common elements of any pressurized system. Their general purpose is to provide a positive means of preventing system pressure from exceeding a preset value, avoiding uncontrolled events that could result in damage to personnel, environment, or assets. Their operating principle and construction are comparatively simple and well understood.

Long term exposure of a relief valve to certain types of process media can result in corrosion, material buildup, or other conditions which may shorten the useful life of the valve, or worse, impair its proper operation. This excessive wear will increase the ongoing cost of maintaining or replacing a prematurely worn valve. One other aspect of relief valves can be the reduction in their seal integrity or force as the system pressure approaches the setpoint. This could possibly lead to fugitive emissions, an undesirable condition.

An effective approach to mitigating some of the effects of exposure to the process media is to install a rupture disc upstream of the safety valve inlet. Isolating a relief or safety valve from the process media through the installation of a rupture disc upstream of the valve inlet eliminates exposure of the costly valve to effects of the media. It is necessary to establish proper rating and selection for the rupture disc to avoid any impairment of the overall operation of the relief valve, but the selection criteria are not complex. A number of benefits can accrue with this concept.

  • Rupture disc isolates the valve from the media, allowing application of less costly valves fabricated of non-exotic materials.
  • Rupture discs are leak free and bubble tight, eliminating possibility of fugitive emissions from the safety relief valve, especially when system pressure may approach valve setpoint.
  • Relief valve inventory can be evaluated for reduction.
  • Longer valve life.
  • Less downtime.

The additional cost for the rupture disc enhancement can have a reasonable payback period, with all factors considered. In any case, the rupture disc protection makes for a cleaner relief valve installation. Rupture discs and holders are available in sizes and materials for most applications. Share your ideas with a valve specialist, combining your process knowledge with their product application expertise to develop an effective solution.

Friday, February 23, 2018

Industrial Diaphragm Valves

sectional drawing weir type diaphragm valve with pneumatic actuator
Section drawing of diaphragm valve, weir type,
with pneumatic actuator.
Image courtesy Gemu Valves, Inc.
Diaphragm valves are named for the means employed in their design to restrict the path of fluid flow through the valve. Most valve designs employ a rigid solid shape which is repositioned in the fluid path to regulate flow. Diaphragm valves are somewhat unique in their use of a flexible material that is deformed by a moving part connected to the valve operating mechanism. The diaphragm acts as the flow restrictor and seat. It also isolates the valve bonnet and stem from the flowing media.

The fluid path and diaphragm positioning and seating enable this valve type to be used for throttling or simple stop operations. They are generally tolerant of particulate matter entrained in the media. Selecting body and diaphragm materials that are compatible with the media are primary elements of achieving a successful application. The diaphragm is a wearing part and should be inspected periodically and replaced when necessary.

Diaphragm valves for industrial use are available in a range of materials and sizes to accommodate light through heavy duty applications.
  • Suitable for inert and corrosive liquid and gaseous media when proper valve body and diaphragm materials are selected
  • Bonnet and valve bodies available in metal or plastic construction
  • Insensitive to particulate media
  • Valve body and diaphragm available in various materials and designs
  • Compact design
  • Automation via pneumatic or electric means
Share your fluid process control challenges with valve application specialists. Leverage your own knowledge and experience with their product application expertise to develop an effective solution.

Sunday, February 18, 2018

Getting Benefit From Waste Steam With a Thermocompressor

steam thermocompressor
Steam thermocompressor enables use of waste steam
in higher pressure applications.
Image courtesy Spirax Sarco
Steam, with its utilization as a means of transferring heat, as well as a motive force, is found in use throughout many industries. The production of steam is a significant cost of operation for any business where it is employed. Steam, after performing its intended function, still contains a comparatively large amount of heat, so methods of recovering or utilizing that heat energy remaining in waste steam is a positive step in conservation.

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 contribute to the bottom line of the operation's balance sheet. It is not uncommon for  energy conservation and efficiency measures contribute to improvement in the overall functioning of the steam utilization equipment or systems. 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 several ways that improve productivity and performance.

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, through reuse, the remaining heat content of the otherwise wasted low pressure steam. The device is compact and simple, with no moving parts or special maintenance requirements. Two general varieties are available. A 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 your steam system challenges with a steam system application specialist. Leverage your own process and facilities knowledge and experience with their product application expertise to develop effective solutions.


Wednesday, February 7, 2018

Plug Valves - Right For Your Application?

industrial plug valve with manual operating handle
Plug valves incorporate design features making them
a positive choice for many fluid process applications.
Image courtesy Fluoroseal, Inc.
There are common components to be found on almost every process system that involves fluid control. Regardless of the operation's scale, pumps, piping, tanks and valves are likely to be part of the system.

Valves, of which there are many types, provide control over the flow rate, direction and routing of fluids in a processing operation. Flow can be started, stopped or modulated between zero and full rate using a properly sized and configured valve. Some valves enable media flow to be diverted to a selection of outlets, in lieu of a single inlet and outlet pair. Specialized valves regulate inlet or outlet pressure, or prevent fluid flow from going in an undesirable direction. All of these capabilities are packaged into differing valve product offerings that present a very large selection array to a process designer or engineer.

Industrial flow control valve types are generally classified according to the structure or arrangement contained within the valve body that provides obstruction to fluid flow. Some of the common types are ball, butterfly, gate, globe, and plug. Surely, there are more valve types, and this article is not intended to list them all. Some of our previous blogs have discussed selection considerations for gate, ball and butterfly valves. This article will focus on one of the oldest valve types, the plug valve.

Plug valves, like ball and butterfly valves, span from fully open to fully closed positions with a shaft rotation of 90 degrees. The “plug” in a plug valve is installed in the flow path within the valve body and rotated by means of a stem or shaft extending to the exterior of the body. Plugs are often tapered toward the bottom and are fitted to a seating surface in the valve body cavity that prevents fluid from bypassing the plug. An opening through the plug, the port, can be shaped to provide particular flow characteristics. There are numerous variants of the basic plug valve which may make it suitable for particular applications. One common variant is the lined or sleeved plug valve, with an insert or interior lining of material that creates an isolating barrier between the valve body and the media. This allows use of less expensive materials for the body construction that may be otherwise subject to corrosion by exposure to aggressive media.

Positive attributes of plug valves.

  • 90 degree rotation from open to closed provides fast operation.
  • With proper configuration, can be well suited for frequent operation.
  • Availability of corrosion resistant liner may provide comparative cost savings because valve body can be constructed of less expensive material.
  • Design is simple and employs a low parts count.
  • Valve can be serviced in place.
  • Generally, low resistance to flow when fully open.
  • Reliable leak-tight service due to tapered plug wedging action, replaceable sleeve, and injection of lubricant in some variants.

Potential issues of concern.

  • Higher friction in the plug closure mechanism may require comparatively higher operating torque than other valve types.
  • Without a specially designed plug, generally not well suited for throttling applications.
  • Rapid shutoff delivered by plug design may not be suitable for some applications where hammering may occur.

Share your fluid control application challenges with a valve and automation specialist. Leverage your own knowledge and experience with their product application expertise to develop an effective solution.

Friday, February 2, 2018

Pressure and Temperature Switches for Rugged Industrial Applications

adjustable pressure switch
This adjustable pressure switch is one of many variants
available to suit every application.
Image courtesy Custom Control Sensors (CCS)
Matching up the most appropriate control device for a processing application, taking all factors into account, may not always result in a selection of the most technologically advanced, complex or full featured solution. Sometimes, all that is needed is a device with a limited performance set, but one that performs its functions reliably in a challenging industrial environment.

Industrial versions of temperature, pressure and differential pressure switches are fitted with appropriate mountings for the process and housings for the installation environment. Hazardous location installation can be accommodated. High current switch ratings and auxiliary functions add to the usefulness of these devices. There are almost countless variants available to accommodate almost every application. Don’t overlook these simple and reliable mechanical devices as candidates for application in temperature and pressure control. Share your application requirements and challenges with product specialists for useful recommendations.



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.


Wednesday, January 10, 2018

Steam Trap For Heavily Contaminated Steam

cast iron float steam trap
The Float Trap series is available in carbon or stainless steel.
Image courtesy Spirax Sarco
Industrial process gear and equipment manufacturers are always tweaking designs, adding features, and creating new product variants in response to the challenges presented by the immeasurably broad range of application and operation scenarios for their products. Spirax Sarco is a globally recognized leader in the design and manufacture of steam system specialties, and has created a rugged steam trap to accommodate some tough challenges.

The company's FTC23 and FTS23 Float Trap products are ball float steam traps suitable for use with saturated and superheated steam. The units can be utilized on process equipment and for drainage of temperature controlled systems. These traps are specifically targeted at applications involving steam that may be carrying solids or incondensable gasses. Solids, if not purged from the system, can accumulate and foul the internal trap mechanism, leading to failure.

The company indicates that the main design feature is a self-cleaning float closing mechanism which maintains safe operation even in the presence of severe contamination. The positioning of the valve and seat also promote the discharge of the condensate, along with entrained contaminants. There is even a manual lever on the exterior of the trap that allows an operator to force the full opening of the valve, regardless of whether condensate is present. This operation facilitates fast removal of contaminants and maintains optimum performance.

The two models differ in their construction materials, with one having a carbon steel body, the other a stainless steel body. Internals are stainless steel on both units.

Share your challenges with the steam system specialists, leveraging your own knowledge and experience with their product application expertise.


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.