Showing posts with label Montana. Show all posts
Showing posts with label Montana. Show all posts

Swanson Flo Markets - New Video

Here's a new short video highlighting the markets that Swanson Flo serves in the upper midwest United States.

Valve Automation Basics: Electric Actuators

Electric Actuator
Electric Actuator Assembly (Limitorque)
Electric actuators bring automation to industrial valve operation, allowing complex processes to be managed and controlled by remotely located control systems.

There are other motive forces used for valve actuators, including hydraulic and pneumatic, but electric actuators carry their own particular set of operating characteristics that make them an advantageous choice for many applications.

Valve actuators are available in uncountable variants to suit every application scenario. There are three basic valve actuation motions.

  • Multi-turn, with repeated rotations of the valve shaft needed to move the valve trim from fully open to fully closed. A gate valve is a multi-turn valve. These are also called linear, with respect to the motion of the closure element. The term "linear", in this case, refers only to the movement of the valve trim and not the flow characteristics of the valve.
  • Part Turn, where a 90 degree rotation of the valve shaft produces a change from opened to closed. Ball valves are in this category.
  • Lever, generally associated with damper control.

Electric Actuator
Completed Electrically Automated Valve
An electric actuator is a combination of motor and gearbox with sufficient torque to change valve trim position. A local self-contained control commands the motor and provides feedback to the process master controller regarding position, travel, torque, and diagnostics. Several interface options are available to facilitate communication between actuator and master controller.

There are numerous considerations to take into account when selecting an electric actuator.

  • Torque needed to effectively operate the subject valve.
  • Actuator enclosure type - wash down, hazardous area, dust, etc.
  • Service area for the assembly - corrosive environment, temperature extremes, and more
  • Valve movement - linear, multi-turn, part turn, lever
  • Operation mode - open and close only, positioning, modulating
  • Frequency or duty cycle - infrequent, frequent, or almost continuous positioning
  • Communication - How will the local controller communicate with the central control system?
  • Electrical - What electric power characteristics are available for operation?
  • Protections - Motor overload, torque limit, others
  • Process Safety - Among other things, what happens if power fails? 

There are certainly other elements to consider when applying an electric actuator for industrial use. Share your valve and actuator requirements and challenges with product specialists, combining your process knowledge with their product application expertise to forge the most effective solutions.

https://swansonflo.com
800-288-7926

Swanson Flo Performance - Full Capability Instrumentation and Valve Service & Repair

In-house repair as well as field service capabilities for process measurement and control.

Swanson Flo Performance supports every process control customer with region-based, full-capability service and repair. Both in-house and in-field. Built on more than 50 years of applications experience and technical knowledge.

  • From valves and instruments to actuation, fabrication and preventative maintenance. 
  • Our technicians are factory-certified. 
  • Shop is factory audited.
  • Total service for process measurement and control
  • Valve actuation facilities – the "Center of Excellence"
  • Instrument calibration, repair, and trouble-shooting services
Call 800-288-7926 or visit https://swansonflo.com


Limitorque MX Actuator Users Instructions, Maintenance, and Spare Parts Manual

Flowserve Limitorque MX
The Flowserve Limitorque MX actuator controls the opening and closing travel of valves and other actuated devices. OPEN and CLOSED limits are protected by an absolute encoder that provides optical sensing of valve position and measures valve position in both motor and handwheel operation.

No battery or backup power supply is required. Output torque is derived from motor speed, temperature, and voltage. If the preset torque is exceeded, the motor shuts off. As a result of this reliable and advanced protection technology, all valve and other actuated devices are protected from potential damage from overload, improper seating, and foreign obstructions.

A range of control and network options is available and can be easily added to the control capabilities already available on a standard actuator.

You can download the Limitorque MX Electronic Actuator User Instructions, Maintenance, and Spare Parts Manual in PDF version from the Swanson Flo site here (8.5MB), or read the embedded version below.

Turbine Flow Meters

Turbine flow meters
Turbine flow meters (Badger Meter / Blancett)
Turbine flow meters are process instruments used in a variety of industrial applications to measure the flow of a fluids. These types of flowmeters operate under the simple principle that the rotation of the turbine will be constant as the turbine is acted upon by a fluid passing through the flowmeter.

Turbine flow meters use the mechanical energy of the fluid to rotate a turbine blade in the flow stream and provide precise and accurate flow measurement. The flow impinging upon the turbine blades causes the rotor to spin. The angular velocity of a turbine flow meter is proportional to flow rate. The rotational velocity of the turbine is interpreted as an electrical frequency output through the use of magnetic pick-ups. As each turbine blade passes by the magnetic pick-up coil, a voltage pulse is generated which is a measure of the flow rate. The total number of pulses gives a measure of the total flow which can be totalized with a maximum error of a single pulse.

The relationship of the angle of the turbine meter blades to the flow stream governs the angular velocity and the output frequency of the meter. The sharper the angle of the turbine blade, the higher the frequency output.

Easy to maintain while also boasting reliability, turbine flow meters are known to be cost-effective solutions that make an ideal device for measuring flow rate. Aside from excellent rangeability, they also provide high response rate and high accuracy compared to other available types of flow meters. Turbine flow meters are sturdy, need very little maintenance, and seldom exhibit much deviation in performance.

Turbine flow meters
Turbine flow meters (Hoffer Flow Controls)
These meters are used in multiple industries to reliably measure the velocity of a variety of liquids, gases and vapors over a very broad range of flow rates, temperatures, and viscosities. Turbine flow meters are used to provide measurement information in cryogenic applications, crude oil production, chemical processing, blending systems, storage, off-loading, product loading, and many other applications across many industries.

Advantages:
  • Accuracy
  • Excellent repeatability and range
  • External power not required
  • Good fro cryogenic applications
  • Good for extreme pressures and temperatures
  • Easy to install
Disadvantages
  • Material availability
  • Not recommended for contaminated media or slurries
  • Error due to wear
For information on any flow control application, contact Swanson Flo by calling 800-288-7926 or visit https://swansonflo.com.

Disassembly, Repair, and Rebuild of the Jordan Mark 78 Control Valve

Jordan Mark 78 Control Valve
The Jordan Mark 78 pneumatic control valve is designed for accurate performance and simplified maintenance. This versatile product can be used on a variety of applications, including viscous/corrosive liquids, process gases or steam in process or utility service.
  • Shutoff: ANSI Class IV or VI
  • Sizes: 1/2" – 2" (DN15 – DN50)
  • End Connections: Threaded, Flanged, Socket Weld, Butt-Weld
  • Body Materials: Bronze, Carbon Steel, Stainless Steel
  • Cv (Kv): up to 50 (up to 43)
  • Trim Materials: Stainless Steel, Monel, Hastelloy C, Alloy 20
  • Seat: ANSI Class IV (Hard Seat); ANSI Class VI Teflon (Soft Seat)
  • Control Ranges: 3-15 psi, 6-30 psi or split ranges (0,2-1,0 bar, 0,4-2,1 bar)
The video below provides a detailed demonstration of how to disassemble, repair, and rebuild the Mark 78 control valve.

800-288-7926 

Understanding Explosion Proof Enclosures Used in Process Control

This is a short video that explains what an explosion-proof enclosure is, what defines it as “explosion-proof”, and the principle behind why its safe to use in explosive or combustible atmospheres.

“Explosion-proof" doesn't mean the enclosure can withstand the forces of an external explosion. It means that the enclosure is designed to cool any escaping hot gases (caused by an internal ignition) sufficiently enough as to prevent the ignition of combustible gases or dusts in the surrounding area.

https://swansonflo.com
800-288-7926

Introduction to Industrial Control Systems

Industrial Control Systems Control systems are computer-based systems that are used by many infrastructures and industries to monitor and control sensitive processes and physical functions. Typically, control systems collect sensor measurements and operational data from the field, process and display this information, and relay control commands to local or remote equipment. In the electric power industry they can manage and control the transmission and delivery of electric power, for example, by opening and closing circuit breakers and setting thresholds for preventive shutdowns. Employing integrated control systems, the oil and gas industry can control the refining operations on a plant site as well as remotely monitor the pressure and flow of gas pipelines and control the flow and pathways of gas transmission. In water utilities, they can remotely monitor well levels and control the wells’ pumps; monitor flows, tank levels, or pressure in storage tanks; monitor water quality characteristics, such as pH, turbidity, and chlorine residual; and control the addition of chemicals. Control system functions vary from simple to complex; they can be used to simply monitor processes—for example, the environmental conditions in a small office building—or manage most activities in a municipal water system or even a nuclear power plant.

Industrial Control SystemsIn certain industries such as chemical and power generation, safety systems are typically implemented to mitigate a disastrous event if control and other systems fail. In addition, to guard against both physical attack and system failure, organizations may establish back-up control centers that include uninterruptible power supplies and backup generators.

There are two primary types of control systems. Distributed Control Systems (DCS) typically are Supervisory Control and Data Acquisition (SCADA) systems typically are used for large, geographically dispersed distribution operations. A utility company may use a DCS to generate power and a SCADA system to distribute it.

process instruments
Field devices and discreet controllers used in control systems
(Foxboro Schneider Electric).
A control system typically consists of a “master” or central supervisory control and monitoring station consisting of one or more human-machine interfaces where an operator can view status information about the remote sites and issue commands directly to the system. Typically, this station is located at a main site along with application servers and an engineering workstation that is used to configure and troubleshoot the other control system components. The supervisory control and monitoring station is typically connected to local controller stations through a hard- wired network or to remote controller stations through a communications network—which could be the Internet, a public switched telephone network, or a cable or wireless (e.g. radio, microwave, or Wi-Fi) network. Each controller station has a Remote Terminal Unit (RTU), a Programmable Logic Controller (PLC), DCS controller, or other controller that communicates with the supervisory control and monitoring station. The controller stations also include sensors and control equipment that connect directly with the working components of the infrastructure—for example, pipelines, water towers, and power lines. The sensor takes readings from the infrastructure equipment—such as water or pressure levels, electrical voltage or current—and sends a message to the controller. The controller may be programmed to determine a course of action and send a message to the control equipment instructing it what to do—for example, to turn off a valve or dispense a chemical. If the controller is not programmed to determine a course of action, the controller communicates with the supervisory control and monitoring station before sending a command back to the control equipment. The control system also can be programmed to issue alarms back to the operator when certain conditions are detected. Handheld devices, such as personal digital assistants, can be used to locally monitor controller stations. Experts report that technologies in controller stations are becoming more intelligent and automated and communicate with the supervisory central monitoring and control station less frequently, requiring less human intervention.

Swanson Flo can help you with control system questions or challenges. Reach them by calling 800-288-7926 or visiting https://swansonflo.com.

Foxboro Magnetic Flowmeter for Chemical and Process Industries

MagPlus
Based on Faraday’s law of induction, Foxboro magnetic meters are a reliable  ow measurement solution with a lower cost of ownership and maintenance, as well as  eld-proven stability to maximize the availability of  ow measurement.

With a wide range of liners and electrodes, the 9700A  owtube is ideal for the Chemical and Process industries. In combination with the IMT30A, IMT31A and IMT33A transmitters, Foxboro offers an innovative solution designed to meet the demands for all chemical applications such as:
  • Clean liquids
  • Mixing of chemicals
  • Demanding applications including corrosive, abrasive liquids • Rapid variation of the pH value
  • For slurries and pastes with high solids content
  • Drilling applications, mining slurries with large particles

See the embedded brochure below, or download your own PDF from this Swanson Flo link.


Butterfly Valves Used in Industrial and Commercial Applications

Automated butterfly control valve
Automated butterfly control valve.
(Valtek)
Industrial process control valves are available in uncountable combinations of materials, types, and configurations. An initial step of the selection procedure for a valve application should be choosing the valve type, thus narrowing the selection field to a more manageable level. Valve "types" can generally be classified by the closing mechanism of the valve.

A butterfly valve is used for stopping or controlling flow of liquids or materials through pipes. The "butterfly" refers to the round, flat disk that allows for flow through the valve. Butterfly valves are a member of the "quarter-turn" valve family, meaning fully open to fully closed in 90 degrees rotation. They are opened and closed via a lever, manual gear operator, pneumatic actuator, or electric actuator. Butterfly valves can be used for on-off service and some varieties are used as control valves. Butterfly valves are generally less expensive than other high flow valves, lighter in weight, and take up less piping length. Since the disk is always in the flow path, butterfly valves always have a pressure drop across the valve.

There are two primary types of butterfly classifications:
  1. So called "rubber lined" butterfly valves (resilient seated) which are best suited for lower pressure, lower temperature, general purpose applications.
  2. High Performance Butterfly Valves (HPBV) which are designed to ANSI pressure classifications and are suited for more robust industrial applications.
Rubber lined butterfly valve
Rubber lined butterfly valve.
(Centerline)
Rubber lined (resilient seated) butterfly valves come in a variety of seating materials, where the disk "jams" in to the seat. This provides a tight closure, but also causes wear on the seat. Seat replacement is part of normal maintenance on these valves. Another characteristic of rubber lined butterfly valves are higher starting and ending torques due to the "jamming" and "unjamming" of the disk in the seat.

High performance butterfly valves have precision machined teflon, or metal seats, and are slightly offset as to lessen the amount of seat-to-disk interference. The disc still is pushed against he seat, but in a much more controlled and measured manner. Seat wear is still an issue, but not like rubber lined valves. Seating and unseating torque effects are much less as well.

Triple offset butterfly
Triple offset butterfly.
(Valtek)
A variation of the HPBV is the triple eccentric butterfly valve which uses a metal seat and a "triple-offset" design, best described as the disk coming "off and away" from the seat. This assures that the disk only contacts the seat at time of full closure, reducing wear on the metal seat. These valves provide excellent shut off in critical applications.

Butterfly valves come in three body styles:
  1. Wafer body, whereby the valve is "sandwiched" and held in place between two pipe flanges and are suitable for lower pressure applications.
  2. Lug style bodies that have threaded "lugs" cast in to the body of the valve and bolts are used to secure the valve for end of line service or keeping the valve in place when the piping is disassembled.
  3. ASME flanged butterfly valves where the valve body is in-between two ASME flanges.
Butterfly valves, like other valve types, have applications where selection and design of one style outperforms another style. Careful consideration and consultation with a valve expert is a first step toward making a good selection. Combine your process know-how with the product application expertise of a professional sales engineer to produce the best solutions to your process control challenges.

Flowserve Valtek MaxFlo 4 Eccentric Rotary Plug Control Valve

Valtek MaxFlo 4 Eccentric Rotary Plug Control Valve
The Flowserve Valtek MaxFlo 4 control valve is a high performance eccentric rotary plug valve designed for the process industry. It features a large capacity, standard hardened trim and superior shaft blow-out protection.

This valve is available in sizes 1 through 12 inches, ASME Class 150, 300 and 600 as well as DIN PN 10, PN16, PN 25, PN40 and PN63. An optional ISA 75.08.01 or DIN EN 558 series 1 long-pattern body makes this valve an easy drop-in replacement for a globe control valve. 

Founded in 1960, Swanson Flo has long maintained our position as an industry leader in process automation with unmatched project success leveraging industry preferred products and services. 

800-288-7926

Worm Gear Valve Operators

Worm gear operator
Worm gear operator (WedgeRock)
Every industrial valve needs a means to open and close, allowing the process to flow.  Worm gear actuators provide a mechanical advantage to make hand operation possible for most quarter-turn butterfly, ball, and plug valves as well as quarter-turn and multi-turn dampers. Gears provide mechanical advantage to an operator providing the force required to open and close the valve.  Torque can be increased or decreased by changing the size of the hand wheel. Manual worm gear operators are relatively inexpensive and require little involvement beyond their in the process line.

Download the WedgeRock RW Series IOM PDF here.

Understanding Biofuels

Ethanol plant
Ethanol Plant
Unlike other renewable energy sources, biomass can be converted directly into liquid fuels, called "biofuels," to help meet transportation fuel needs. The two most common types of biofuels in use today are ethanol and biodiesel. Ethanol is an alcohol, the same as in beer and wine (although ethanol used as a fuel is modified to make it undrinkable). It is most commonly made by fermenting any biomass high in carbohydrates through a process similar to beer brewing. Today, ethanol is made from starches and sugars, but scientists are developing technology to allow it to be made from cellulose and hemicellulose, the fibrous material that makes up the bulk of most plant matter.

Ethanol can also be produced by a process called gasification. Gasification systems use high temperatures and a low-oxygen environment to convert biomass into synthesis gas, a mixture of hydrogen and carbon monoxide. The synthesis gas, or "syngas," can then be chemically converted into ethanol and other fuels.

Ethanol is mostly used as blending agent with gasoline to increase octane and cut down carbon monoxide and other smog-causing emissions. Some vehicles, called Flexible Fuel Vehicles, are designed to run on E85, an alternative fuel with much higher ethanol content than regular gasoline.

Biodiesel is made by combining alcohol (usually methanol) with vegetable oil, animal fat, or recycled cooking grease. It can be used as an additive (typically 20%) to reduce vehicle emissions or in its pure form as a renewable alternative fuel for diesel engines. Research into the production of liquid transportation fuels from microscopic algae, or microalgae, is reemerging. These microorganisms use the sun's energy to combine carbon dioxide with water to create biomass more efficiently and rapidly than terrestrial plants. Oil-rich microalgae strains are capable of producing the feedstock for a number of transportation fuels—biodiesel, "green" diesel and gasoline, and jet fuel—while mitigating the effects of carbon dioxide released from sources such as power plants.

Swanson Flo, and its subsidiary BioFuels Automation, has decades of experience in the renewable fuels industry. Their team is responsible for the products in over 90% of plants nationwide and are uniquely positioned to keep the existing bio-refineries operational while minimizing downtime. For more information about the processing of renewable fuels, contact Swanson Flo by calling 800-288-7926 or visiting https://www.swansonflo.com.

Industrial Valve Actuators: An Overview

Pneumatic Actuator
Pneumatic Actuator
(Limitorque)
Valves are essential to industries which constitute the backbone of the modern world. The prevalence of valves in engineering, mechanics, and science demands that each individual valve performs to a certain standard. Just as the valve itself is a key component of a larger system, the valve actuator is as important to the valve as the valve is to the industry in which it functions. Actuators are powered mechanisms that position valves between open and closed states; the actuators are controllable either by manual control or as part of an automated control loop, where the actuator responds to a remote control signal. Depending on the valve and actuator combination, valves of different types can be closed, fully open, or somewhere in-between. Current actuation technology allows for remote indication of valve position, as well as other diagnostic and operational information. Regardless of its source of power, be it electric, hydraulic, pneumatic, or another, all actuators produce either linear or rotary motion under the command of a control source.

Thanks to actuators, multiple valves can be controlled in a process system in a coordinated fashion; imagine if, in a large industrial environment, engineers had to physically adjust every valve via a hand wheel or lever! While that manual arrangement may create jobs, it is, unfortunately, completely impractical from a logistical and economic perspective. Actuators enable automation to be applied to valve operation.
Electric actuator
Electric Actuator
(Limitorque)

Pneumatic actuators utilize air pressure as the motive force which changes the position of a valve. Pressurized-liquid reliant devices are known as hydraulic actuators. Electric actuators, either motor driven or solenoid operated, rely on electric power to drive the valve trim into position. With controllers constantly monitoring a process, evaluating inputs, changes in valve position can be remotely controlled to provide the needed response to maintain the desired process condition.

Large butterfly valve with actuator
Large butterfly valve with actuator.
Manual operation and regulation of valves is becoming less prevalent as automation continues to gain traction throughout every industry. Valve actuators serve as the interface between the control intelligence and the physical movement of the valve. The timeliness and automation advantages of the valve actuators also serve as an immense help in risk mitigation, where, as long as the system is functioning correctly, critical calamities in either environmental conditions or to a facility can be pre-empted and quickly prevented. Generally speaking, manual actuators rely on hand operation of levers, gears, or wheels, but valves which are frequently changed (or which exist in remote areas) benefit from an automatic actuator with an external power source for a myriad of practical reasons, most pressingly being located in an area mostly impractical for manual operation or complicated by hazardous conditions.

Thanks to their versatility and stratified uses, actuators serve as industrial keystones to, arguably, one of the most important control elements of industries around the world. Just as industries are the backbones of societies, valves are key building blocks to industrial processes, with actuators as an invaluable device ensuring both safe and precise operation.

Visual Demonstration of Cavitation and its Adverse Effects on Control Valves and Pumps

Fluid passing through a control valve experiences changes in velocity as it enters the narrow constriction of the valve trim (increasing velocity) then enters the widening area of the valve body downstream of the trim (decreasing velocity). These changes in velocity result in the fluid molecules’ kinetic energies changing as well. In order that energy be conserved in a moving fluid stream, any increase in kinetic energy due to increased velocity must be accompanied by a complementary decrease in potential energy, usually in the form of fluid pressure. This means the fluid’s pressure will fall at the point of maximum constriction in the valve (the vena contracta, at the point where the trim throttles the flow) and rise again (or recover) downstream of the trim:


If fluid being throttled is a liquid, and the pressure at the vena contracta is less than the vapor pressure of that liquid at the flowing temperature, the liquid will spontaneously boil. This is the phenomenon of flashing. If, however, the pressure recovers to a point greater than the vapor pressure of the liquid, the vapor will re-condense back into liquid again. This is called cavitation.

As destructive as flashing is to a control valve, cavitation is worse. When vapor bubbles re-condense into liquid they often do so asymmetrically, one side of the bubble collapsing before the rest of the bubble. This has the effect of translating the kinetic energy of the bubble’s collapse into a high-speed “jet” of liquid in the direction of the asymmetrical collapse. These liquid “microjets” have been experimentally measured at speeds up to 100 meters per second (over 320 feet per second). What is more, the pressure applied to the surface of control valve components in the path of these microjets is intense. Each microjet strikes the valve component surface over a very small surface area, resulting in a very high pressure (P = F/A ) applied to that small area. Pressure estimates as high as 1500 newtons per square millimeter (1.5 giga-pascals, or about 220000 PSI!) have been calculated for cavitating control valve applications involving water.

Water Quality Analyzers for Ultra-pure, Industrial, and Drinking Water Systems

Dissolved Oxygen Analyzer
In the operation of an industrial process, there can be any number of reasons for analyzing water quality. Safety, regulatory compliance, operating efficiency, and process control are a few of the broader categories.

Waltron has been an active participant in the water chemistry and analysis field for over 100 years. The company's focus started with boiler feedwater and has expanded over many years to include online analyzers for process water in a broad range of industries.
  • Power Generation
  • Petrochemical
  • Pulp and Paper
  • Water and Wastewater
  • Electronics and Semiconductor
  • Environmental
  • Pharmaceutical
Waltron process water analyzers provide ease of use, minimal maintenance, and a low service life, delivering a low total cost of ownership. Various technologies are applied, providing specific and accurate analysis for a range of contaminants in ultra-pure, industrial, or drinking water systems.
  • Copper
  • Dissolved Hydrogen
  • Dissolved Oxygen
  • Ethylene Glycol
  • Hardness
  • Hydrazine
  • Iron
  • Oil in Water
  • Phosphate
  • Silica
  • Sodium
Included below is a short version product line sheet, showing the company's line of analyzers. Share your water quality monitoring challenges with a product specialist. Incorporating your process knowledge with their expertise will produce the best solution.

Schneider Electric Foxboro Measurement and Control Product Catalog

Measurement and Control Product CatalogSchneider Electric / Foxboro provides customers a complete solution - from instruments in the field to the control room - to enable customers to optimize their assets-people, equipment, plant. With a history of innovation, Foxboro Field Devices provides solutions across a wide range of industries, including Energy, Oil, Gas & Refining, Renewable Fuels, Nutrition And Life Sciences, Process Automation, Water & Wastewater.

Foxboro / Schneider Electric range of products in Measurement and Instrumentation include:
  • Flow
  • Level
  • Pressure
  • Process Liquid Analytical
  • Temperature
  • Control
  • Data Acquisition & Configurator
  • Pneumatic
  • Valve Positioners
  • Accutech
Visit this page on the Swanson Flo website to download your full PDF version.

You can easily specify many instruments and accessories described in this catalog. Sections covering our most popular items include all the technical data you need to know for most applications. To specify the appropriate item, simply follow the step-by-step procedure at the end of each description. Please feel free to contact Swanson Flo for help.

New Product Alert: The Jordan Mark 75PTP Sliding Gate Control Valve

Jordan Mark 75PTP
Jordan Mark 75PTP
The Jordan Mark 75PTP is a Mark 75 wafer style control valve with an 80mm (1" - 2") Stainless Steel Piston Actuator. The Gemu cPOS Smart Positioner is standard and required for control applications. For on/off service, the valve may supplied without a positioner. JVCV Should be used for sizing selection.

The Mark 75PTP provides great capacity in a com-pact wafer style body. A 2" Mark 75PTP provides 72 Cv (62 Kv). (Refer to Cv Capacity Charts for information concerning all line sizes).

The Mark 75PTP features a 'T' slot design connection to the disc. This connection allows for quick and easy reversing of functions. Instead of having to go into the actuator to change action, all that is needed in a Mark 75PTP is to rotate the seats 180°. With this simple rotation, the valve can go from reverse acting to direct acting (or vice versa).The stroke length of the Mark 75PTP is a slightly longer stroke than standard sliding gate valves. This longer stroke enables better turndown. Combined with the capacity of the Mark 75PTP, the in-creased turndown makes for a great control valve.





Limitorque Actuator Product Range

Limitorque has 90 years experience providing electric actuators to safely operate automated valves that protect people and property. The products that Limitorque offer are:
  • Intrusive Multi-Turn Actuators - L120 and SMB Series
  • Non-Intrusive Multi-Turn Actuators - MX Series
  • Non-Intrusive Quarter-Turn Electric Actuators - QX Series
  • Gas Powered Actuators - LDG Direct Gas Actuator
  • Hydraulic Actuators - LHS and LHH Series
  • Pneumatic Actuators - LPS and LPC Series
  • Multi-Turn Gearboxes - V Series and SR Series
  • Quarter-Turn Gearboxes - WG Series and HBC Series
For more information on Limitorque watch the video below and visit https://www.swansonflo.com or call 800-288-7926.

Understanding Linear, Equal Percentage, and Quick Open Control Valve Flow Curves

Flowserve Valtek Control Valve
Flowserve Valtek Control Valve
Flow characteristics, the relationship between flow coefficient and valve stroke, has been a subject of considerable debate. Many valve types, such as butterfly, eccentric disk and ball valves, have an inherent characteristic which cannot be changed (except with characterizable positioner cams). Flow characteristics of globe valves can be determined by the shape of the plug head.

The three most common types of flow characteristics are quick opening, equal percentage and linear. The figure below shows the ideal characteristic curve for each. These characteristics can be approximated by contouring the plug. However, inasmuch as there are body effects and other uncontrollable factors, plus the need for maximizing the flow capacity for a particular valve, the real curves often deviate considerably from these ideals. When a constant pressure drop is maintained across the valve, the characteristic of the valve alone controls the flow; this characteristic is referred to as the “inherent flow characteristic.” “Installed characteristics” include both the valve and pipeline effects. The difference can best be understood by examining an entire system.

Equal Percentage
Control valve flow curves
Control valve flow curves.


Equal percentage is the characteristic most commonly used in process control. The change in flow per unit of valve stroke is directly proportional to the flow occurring just before the change is made. While the flow characteristic of the valve itself may be equal percentage, most control loops will produce an installed characteristic approaching linear when the overall system pressure drop is large relative to that across the valve.

Linear

An inherently linear characteristic produces equal changes in flow per unit of valve stroke regardless of plug position. Linear plugs are used on those systems where the valve pressure drop is a major portion of the total system pressure drop.

Quick Open

Quick open plugs are used for on-off applications designed to produce maximum flow quickly.

This information provided courtesy of Flowserve Valtek. Share your control valve requirements and challenges with a valve specialist, combining your own process knowledge and experience with their product application expertise to develop effective solutions.