Showing posts with label Neles. Show all posts
Showing posts with label Neles. Show all posts

Wednesday, January 31, 2018

Industrial Valve Actuators

Valve actuators are selected based upon a number of factors including torque necessary to operate the valve and the need for automatic actuation. Types of actuators include manual handwheel, manual lever, electrical motor, pneumatic, and solenoid. All actuators except manual handwheel and lever are adaptable to automatic actuation.

Handwheel
Handwheel (Metso)
Manual Actuators

Manual actuators are capable of placing the valve in any position but do not permit automatic operation. The most common type mechanical actuator is the handwheel. This type includes handwheels fixed to the stem and handwheels connected to the stem through gears.

Electric Motor Actuators

Electric Actuator
Electric Actuator (Limitorque)
Electric motors permit manual, semi-automatic, and automatic operation of the valve. Motors are used mostly for open-close functions, although they are adaptable to positioning the valve to any point opening. The motor is usually a, reversible, high speed type connected through a gear train to reduce the motor speed and thereby increase the torque at the stem. Direction of motor rotation determines direction of disk motion. The electrical actuation can be semi-automatic, as when the motor is started by a control system. A handwheel, which can be engaged to the gear train, provides for manual operating of the valve. Limit switches are normally provided to stop the motor automatically at full open and full closed valve positions. Limit switches are operated either physically by position of the valve or torsionally by torque of the motor.

Pneumatic Actuators

Pneumatic Actuator
Pneumatic Actuator
(Metso Neles)
Pneumatic actuators provide for automatic or semi-automatic valve operation. These actuators translate an air signal into valve stem motion by air pressure acting on a vane, diaphragm, or piston connected to the stem. Pneumatic actuators are used in throttle valves for open-close positioning where fast action is required. When air pressure closes the valve and spring action opens the valve, the actuator is termed direct-acting. When air pressure opens the valve and spring action closes the valve, the actuator is termed reverse-acting. Double acting actuators have air supplied to both sides of the vane, diaphragm, or piston. The differential pressure across the diaphragm positions the valve stem. Automatic operation is provided when the air signals are automatically  controlled by circuitry. Semi-automatic operation is provided by manual switches in the circuitry to the air control valves.


Hydraulic Actuators

Hydraulic actuators provide for semi-automatic or automatic positioning of the valve, similar to the pneumatic actuators. These actuators use a piston to convert a signal pressure into valve stem motion. Hydraulic fluid is fed to either side of the piston while the other side is drained or bled. Water or oil is used as the hydraulic fluid. Solenoid valves are typically used for automatic control of the hydraulic fluid to direct either opening or closing of the valve. Manual valves can also be used for controlling the hydraulic fluid; thus providing semi-automatic operation.

Solenoid Actuated Valves

Solenoid Valve
Solenoid Valve (ASCO)
Solenoid actuated valves provide for automatic open-close valve positioning. Most solenoid actuated valves also have a manual override that permits manual positioning of the valve for as long as the override is manually positioned. Solenoids position the valve by attracting a magnetic slug attached to the valve stem. In single solenoid valves, spring pressure acts against the motion of the slug when power is applied to the solenoid. These valves can be arranged such that power to the solenoid either opens or closes the valve. When power to the solenoid is removed, the spring returns the valve to the opposite position. Two solenoids can be used to provide for both opening and closing by applying power to the appropriate solenoid.

Single solenoid valves are termed fail open or fail closed depending on the position of the valve with the solenoid de-energized. Fail open solenoid valves are opened by spring pressure and closed by energizing the solenoid. Fail closed solenoid valves are closed by spring pressure and opened by energizing the solenoid. Double solenoid valves typically fail "as is." That is, the valve position does not change when both solenoids are de-energized.

One application of solenoid valves is in air systems such as those used to supply air to pneumatic valve actuators. The solenoid valves are used to control the air supply to the pneumatic actuator and thus the position of the pneumatic actuated valve.

Mead O'Brien can handle any valve actuation requirement you have. Contact them by calling (800) 892-2769 or by visiting https://meadobrien.com.

Sunday, December 24, 2017

Metso Neles T5 Series Top Entry Rotary Ball Valves

Metso's Neles T5
Metso's Neles® T5 series top entry rotary ball valves are designed to meet the requirements of chemical, petro-chemical and refining industries with improved process safety and efficiency of plant.

T5 series valves with famous trunnion mounted Stemball® design are suitable with wide rangeability for demanding heavy duty rotary control applications such as crude oil, hot residual oil, LPG and other hydrocarbon gases and vapors under medium and high pressures. 

Unique Stemball® design combined with anti-cavitation and low noise Q-trim technology are making the T5 series valve most suitable with wide rangeability for demanding control applications like anti surge and blow down services. The new high noise reduction Q2-trim is available for gas applications.

Tuesday, October 24, 2017

The Neles B1 Series Actuator

B1-Series
Neles B1 Series
Metso's Neles double acting and spring return B1-Series piston type actuators are designed for use in both modulating control and on-off service. The series B1C and B1J are designed to ISO 5211/1 when Metso linkages are utilized. These actuators offer an extremely long cycle life and are well suited to operate almost any type of rotary valve.

When "stay put" is the requirement, the double acting B1C series is the choice. This series is available in several sizes with torque outputs from 40 Nm to 100 000 Nm (29.5 lbf ft to 73 756 lbf ft) for maximum supply pressure of 10 bar (145 psi).

If a failure mode is required, the spring return B1J series should be selected. This line offers a self-contained spring cartridge to provide failure in either the open or closed position. The spring return actuators are available with a mid-range spring for a 4 bar (58 psi) supply range, a lighter spring for lower supply pressure of 3 bar (44 psi) range and a stronger spring for a 5.5 bar (80 psi) range. These actuators offer torque outputs from 25 Nm to 12000 Nm (18,5 lbf ft to 8851 lbf ft) for maximum supply pressure of 8.5 bar (124 psi).

Adjustable travel stops

As with any Neles pneumatic/hydraulic actuator, adjustable travel stops are standard for both the open and closed positions. End of stroke turning angle range is 85° to 95°. Optional travel stops 0° to 90° are also available.

Wear resistant bearings

High quality bearings provide support on the upper and lower portions of the lever arm to reduce friction and expand the life of both the lever arm and the housing.
Corrosion resistance

The epoxy painted actuators have housings of rugged cast iron, with light-weight aluminum cylinders anodized for added corrosion resistance. Travel stops are stainless steel.

Self-contained spring cartridge

The springs in the B1J actuator are contained in a cartridge for added reliability and easy maintenance.

Spring to open or close capability

The standard spring return actuator on the ball valve can provide spring-to-close or spring-to-open operation sim- ply by changing the mounting position by 90°. On a high performance butterfly valve, the standard unit offers spring-to-close operation. An optional B1JA model is available for spring-to-open requirements.

High-and-low temperature construction

The standard unit can be used in temperatures up to 70 °C (158 °F). High temperature construction is available for temperatures up to 120 °C (248 °F). The standard unit can be used down to -20 °C (-4 °F). A low temperature design is available for -40° to +70 °C (-40° to 158 °F ), arctic service please refer type coding.

High cycle option

For applications where very fast and high frequency operation is required.

ATEX compatibility

Actuator construction ATEX approved.

Oversized cylinder options

The oversized cylinders (B1C 60, 75, 602, 752) are used whenever the supply pressure is limited, thus the actuators can achieve the required torques with a lower supply pressure level.

Override options

Available override devices include a manual centerpiece handle, a manual handwheel override, and a manual hydraulic override for high torque applications.

Emergency shut-down

Emergency Shut-Down (ESD) valves utilizing B1J actuators are offered to assure operation in the event of a fire or plant malfunction.

For more information about Metso Neles actuators, visit http://www.meadobrien.com or call  (800) 892-2769.

Sunday, July 16, 2017

Industrial Valve Actuator Basics

Electric actuator
Electric actuator (Limitorque)
Actuators are devices which supply the force and motion to open and close valves. They can be manually, pneumatically, hydraulically, or electrically operated. In common industrial usage, the term actuator generally refers to a device which employs a non-human power source and can respond to a controlling signal. Handles and wheels, technically manual actuators, are not usually referred to as actuators. They do not provide the automation component characteristic of powered units.

The primary function of a valve actuator is to set and hold the valve position in response to a process control signal. Actuator operation is related to the valve on which it is installed, not the process regulated by the valve. Thus a general purpose actuator may be used across a broad range of applications.
Pneumatic actuator
Pneumatic actuator (Metso Neles)

In a control loop, the controller has an input signal parameter, registered from the process, and compares it to a desired setpoint parameter. The controller adjusts its output to eliminate the difference between the process setpoint and process measured condition. The output signal then drives some control element, in this case the actuator, so that the error between setpoint and actual conditions is reduced. The output signal from the controller serves as the input signal to the actuator, resulting in a repositioning of the valve trim to increase or decrease the fluid flow through the valve.

An actuator must provide sufficient force to open and close its companion valve. The size or power of the actuator must match the operating and torque requirements of the companion valve. After an evaluation is done for the specific application, it may be found that other things must be accommodated by the actuator, such as dynamic fluid properties of the process or the seating and unseating properties of the valve. It is important that each specific application be evaluated to develop a carefully matched valve and actuator for the process.

Hydraulic and electric actuators are readily available in multi-turn and quarter-turn configurations. Pneumatic actuators are generally one of two types applied to quarter-turn valves: scotch-yoke and rack and pinion. A third type of pneumatic actuator, the vane actuator, is also available.

For converting input power into torque, electric actuators use motors and gear boxes while pneumatic actuators use air cylinders. Depending on torque and force required by the valve, the motor horsepower, gearing, and size of pneumatic cylinder may change.
Linear pneumatic actuator
Linear pneumatic actuator (Neles)

There are almost countless valve actuator variants available in the industrial marketplace. Many are tailored for very narrow application ranges, while others are more generally applied. Special designs can offer more complex operating characteristics. Ultimately, when applying actuators to any type of device, consultation with an application specialist is recommended to help establish and attain proper performance, safety and cost goals, as well as evaluation and matching of the proper actuator to the valve operation requirements. Share your fluid process control requirements with a specialist in valve automation, combining your own process knowledge and experience with their product application expertise to develop effective solutions.

Tuesday, July 11, 2017

Segmented or V Ported Ball Valves

Metso Neles segment ball valve
Metso Neles segment ball valve
Ball, plug and butterfly valves all belong to a class of valves commonly referred to as "quarter-turn" valves. This refers the 90 deg (angular) rotation required to go from full closed, to full open position.

In most cases standard ball, plug, or butterfly valves are not the best choice as control valves (where the process media has to be modulated or throttled). Standard ball, plug and butterfly valves usually introduce very non-linear, dynamic flow coefficients. Furthermore, they can introduce undesirable turbulence to your piping system.

As a means to linearize flow coefficients and reduce turbulent flow, the machining, or characterization, of the valve disk is done so that the machined shape allows for more optimized flow.

For ball valves in particular, machining the ball's flow port with a "V", or even by machining the ball more radically, can deliver excellent flow curves. A term for a more radically machined ball is the "segment ball" (sometimes called "segmented").  In the following video you can see how a Metso Neles segment ball valve is designed to provide excellent control.

For more information about Metso Neles valves, contact Mead O'Brien at  (800) 892-2769 or visit http://meadobrien.com.

Sunday, January 29, 2017

A Look Inside the Neles NDX Intelligent Valve Controller

intelligent valve controller
Neles intelligent valve controller 
Metso’s Neles NDX is the next generation intelligent valve controller working on all single acting control valves and in all industry areas. It guarantees end product quality in all operating conditions with incomparable performance, unique diagnostics, and years of reliable service.

Operating Principle:

The NDX is a 4–20 mA powered micro-controller based intelligent valve controller. The device contains a local user interface enabling configuration and operation without opening the device cover. Configuration and operation can also be made remotely by PC with asset management software connected to the control loop.

After connections of electric signal and pneumatic supply, the micro-controller (μC) continuously reads measurements:
Neles NDX
Click for larger view
  • Input signal 
  • Valve position with contactless sensor (α), 
  • Actuator pressure (I) 
  • Supply pressure (S) 
  • Device temperature
Advanced self­-diagnostics guarantee that all measurements operate correctly.

Powerful micro-controller calculates a control signal for I/P converter (prestage). I/P converter controls the operating pressure to the pneumatic relay (output stage). Pneumatic relay moves and actuator pressure changes accordingly. The changing actuator pressure moves the control valve. The position sensor measures the valve movement. The control algorithm modulates the I/P converter control signal until the control valve position matches the input signal.

The video below demonstrates the NDX's operation. Below the video is the complete installation, maintenance and operation manual for your convenience.




Monday, November 21, 2016

Triple Eccentric Disc Valve, Metal Seated, with Flow Balancing Trim

Triple Eccentric Disc Valve Metal Seated with Flow Balancing Trim
Neles Triple Eccentric Disc
Valve, Metal Seated with
Flow Balancing Trim

TRIPLE ECCENTRIC SEATING PRINCIPLE

The disc of the valve is machined to close tolerances to create an elliptical shape similar to an oblique slice taken from a solid metal cone. When the valve is closed, the elliptical disc at the major axis displaces the seat ring out- ward, causing it ring to contact the disc at the minor axis. When the valve is opened, the contact is released and the seat ring returns to its original circular shape.

CONTROL STABILITY AND SUPERIOR TIGHTNESS

The S-DISC® control valve unit provides outstanding control performance and excellent long-lasting tightness in the same valve. The very simple and robust construction guarantees long trouble-free operation and maximum reliability.

The S-DISC design consists of a standard NELDISC® triple eccentric disc valve equipped with a flow-balancing trim. The trim has been located on the downstream side of the valve body. The ingenious idea of this design is to transfer fluid forces out of the disc to the body. 
triple eccentric disc valve

triple eccentric disc valveFigures 2 and 3 illustrate the flow treatments with a concentric-type conventional butterfly valve compared to the S-DISC-design. The S-DlSC design offers stable flow control and reduced dynamic torque, noise level and vibrations. The dynamic behavior of the valve is very smooth and stable, which means less load on the shaft bearings, less required torque, smaller actuators and more economical control unit total costs. All of the excellent features of the standard NELDISC are available.

The most standard NELDISC can be easily modified to the S-DISC design, just by changing the flange ring.


FEATURES
  • Excellent flow and control performance.
  • Wide temperature range from -200 ... +600 °C /-330 ... +1110 °F.
  • Reduced dynamic torque and noise.
  • Mechanical and flow dynamic stability allows higher pressure drop service than a conventional disc.
  • ASME 150/PN 20, ASME 300/PN 40 and ASME 600/
  • PN 100.
  • Sizes DN 80...1500/3"...60"
For more information, visit http://www.meadobrien.com or call (800) 892-2769 for immediate service.

Tuesday, December 29, 2015

The Rotary Globe Control Valve

Neles Rotary Control Valve
Neles Rotary Control Valve
Neles, a division of Metso, offers their "RotaryGlobe" control valve designed to control a wide range of process liquids, gases and vapors. Its provides reliable and rugged construction and is available with a variety of different trim choices.  An excellent candidate for general, difficult and even severe service control valve applications for many industries including chemical, petrochemical, water treatment, pulp and paper, and power generation. The Neles RotaryGlobe valve provides excellent control accuracy with the inherent benefits of a rotary valve. The optimized design results in reliability and control stability and also reduces lifetime costs and maintenance needs.

See the video below for a "look inside".

Friday, November 13, 2015

Eccentric Rotary Plug Control Valves

Eccentric plug valve
Eccentric plug valve
(courtesy of Neles/Metso)
A plug valve is typically a quarter-turn (90 deg rotation) on-off valve, while eccentric plug valves are often used for control applications. The plug may be cylindrical or tapered, and may be designed with a variety of port patterns. End connections are typically flanged, hub type, or butt weld.

Eccentric rotary plug valves are designed for liquid, gas, vapor and slurry control in general and demanding applications. They provide excellent control performance, and their capability to handle impure fluids makes them well suited in refining, petrochemical, chemical, natural gas, and fertilizer manufacturing applications.

The design of an eccentric plug valve uses a modified plug design (basically a plug cut in half) which is well suited for applications that require a higher seating force, but with minimal friction when cycling from open to closed position. Eccentric plug valves also provide improved shut off capabilities without significant increases in operating torque. This style valve is used for a wide range of flow control and isolation applications including clean water, dirty water, sewage, sludge, and slurries.