Showing posts with label control valve. Show all posts
Showing posts with label control valve. Show all posts

The Samson 82.7 Rotary Plug Control Valve

Samson 82.7 Rotary Plug Control Valve
The Samson 82.7 double eccentric rotary plug control valve is designed for standard and critical service applications, including process events such as erosion, abrasion, corrosion, cavitation, and flashing. The double eccentric rotary plug design increases flow capacities with only minor reduction in the pressure recovery factor making the design an ideal replacement for linear globe control designs even with cavitation and flashing process conditions present.

The 82.7 control valve has several standard options such as temperature extensions, heating jacket, special packing designs, noise attenuation and cavitation prevention trim sets, etc. The Vetec 82.7 can be assembled with a pneumatic, electric, hydraulic, or electro-hydraulic actuator also offered by the SAMSON group to complete the control valve construction. These control valves are designed according to the modular assembly principle, can be equipped with SAMSON GROUP actuators and valve accessories such as positioners, limit switches, and solenoid valves.



For more information contact Ives Equipment. Call their main office at (877) 768-1600 of visit their web site at https://ivesequipment.com.

Reversing the Failure Mode of a SAMSON 3271/3277 Actuator from Fail Open to Fail Close


INSTRUCTIONS

WARNING: Actuators with preloaded springs are under tension. They can be identified by three long bolts protruding from the bottom of the actuator. These should be removed last, and installed first upon re-assembly.
  1. With the actuator removed from the valve, unscrew the nuts and bolts on the diaphragm case.
  2. Lift off the top diaphragm case.
  3. Remove the diaphragm plate assembly consisting of the diaphragm plate, diaphragm, and actuator stem from the actuator case.
  4. Remove the springs.
  5. Clamp the bottom section of the actuator stem into a vise using protective jaws, ensuring the actuator stem is not damaged.
  6. Remove the collar nut.
  7. Remove the diaphragm plate from the actuator stem, flip upside-down and place them back onto the actuator stem.
  8. Re-install the collar nut.
  9. If necessary, apply a suitable lubricant to the actuator stem.
  10. Install the diaphragm plate assembly together with the actuator stem pointing downward into the bottom diaphragm case.
  11. Place the springs onto the diaphragm plate, centering them in the intended recesses. The final actuator spring range will determine the appropriate springs to be installed.
  12. Place the top of the actuator case onto the assembly. Ensure that the air connections on the cases are correctly aligned with each other.
  13. Fasten the top and bottom diaphragm cases together using the nuts and bolts. Observe tightening torques.
ABOUT THE SAMSON 3271/3277

The Type 3271 pneumatic rolling diaphragm actuator is designed for all industrial applications. This actuator is a linear motion device ideal for valve sizes ranging from the micro-flow valves to large 20"+ globe control valves.

The Type 3277 pneumatic rolling diaphragm actuator with an integrated accessory attachment area is designed for all industrial applications. This actuator is a linear motion device ideal for valve sizes ranging from the micro-flow valves to 4" globe control valves.

The thrust force of the actuator depends on the actuator area, pneumatic supply pressure, spring stiffness, distance traveled, initial compression of the spring, the number of springs internal to the actuator, etc.

The Type 3271 and Type 3277 Pneumatic Actuators contain a rolling diaphragm and internal springs and have the following special features:
  • Low overall height
  • Powerful thrust at high stroking speed
  • Low friction
  • Various bench ranges by varying the number of springs or
  • their compression
  • No special tools required to change the bench range or to
  • reverse the direction of action (also version with handwheel)
  • Permissible operating temperatures from –60 to +120 °C
For more information on SAMSON Controls, contact Ives Equipment by calling 877-768-1600 or visiting https://ivesequipment.com.

The Samson 3291 and 3255 Series Control Valves

Samson Controls, located in Baytown, TX, manufactures high-performance, industrial control valves designed to withstand the toughest applications.

Samson 3291
Samson 3291
Samson 3291

The Samson 3291 control valve was specifically developed for heavy duty applications in the oil and gas industry. The construction is based on the proven SAMSON valve design, with one significant difference: while the seats in SAMSON valves are normally screwed in place, the 3291 has the seat held in place by a cage retainer. Unlike typical cage guided control valves, the 3291 control valve utilizes a top and seat guided design by means of a V-port plug. This open flow-path design minimizes friction and allows for the passage of small particulates without clogging the valve or getting “trapped” between the piston and cage. To download the Samson 3291 Control Valve brochure visit this page.

The Samson 3291 Special Length Version is a direct replacement for legacy split body valves without the need for spool pieces, piping modifications, or on-site modifications.

Samson 3522 "Little Tex"
Samson 3522 "Little Tex"

Samson 3522 "Little Tex"

The Type 3522 threaded seat control valve is designed for standard process engineering applications with high industrial requirements for control and quality. This control valve offers a wide range of trim sets to meet required flow coefficient and sealing methods as would be found in general application type control valves. The Type 3522 can be assembled with a pneumatic, electric, hydraulic, or electro-hydraulic actuator also offered by the SAMSON group to complete the control valve construction. To download the Samson 3522 Control Valve brochure visit this page.




An Industrial Valve Positioner that Offers Decisive Advantages

SIPART ® PS2 electro-pneumatic valve positioner
The SIPART ® PS2 electro-pneumatic valve positioner is used to control the final control element of pneumatic linear or part-turn valve actuators. The electro-pneumatic valve positioner moves the actuator to a valve position corresponding to the setpoint. Additional function inputs can be used to block the valve or to set a safety position. A binary input is present as standard in the basic device for this purpose.

The SIPART PS2 smart valve positioner is characterized by significant advantages compared to conventional devices, such as:
  • Only one device version for linear and part-turn valve actuators
  • Simple operation and programming using three keys and a two-line LCD
  • Automatic startup function with self-adjustment of zero and span
  • Manual operation without additional equipment
  • Selectable or freely-programmable characteristics
  • Minimum air consumption
  • Selectable setpoint and manipulated variable limiting
  • Programmable "tight shut-off function"
For more information about the Siemens SIPART 2 positioner download the detailed product brochure from this link,  or visit http://www.ivesequipment.com.

Industrial Control Valve Actuator Operating Principles

Control valve actuators control fluid in a pipe by varying the orifice size through which the fluid flows. Control valves contain two major components, the valve body and the valve actuator. The valve body provides the fluid connections and immovable restrictor comprised a valve stem and plug that is in contact with the fluid that varies the flow.

The valve actuator is the component that physically moves the restrictor to vary the fluid flow. Three actuator types are used in control valves and they include spring and diaphragm, solenoid, and motor. As the name suggests the spring in diaphragm actuator uses a spring and a diaphragm to move the valve stem and plug.

A 15 PSI pneumatic signal enters the housing at the top of the actuator. As pressure is exerted on the diaphragm a downward force is applied against the spring which moves the restrictor. The diaphragm moves until it creates an equal but opposing force against the spring at which time the motion stops as the plug meets the valve seat. With no air pressure the restrictor is pushed upward by the spring to act as a normally open control valve. To vary the position of the restrictor and flow through the valve, a current to pressure transducer can be used to provide a three to 15 PSI signal to the diaphragm.  At 3 PSI the valve is maintained open, and 15 PSI the valve is maintained closed. Pressures between the three to 15 PSI range proportionally change the flow of the valve. For example a pressure of 9 PSI applied to the diaphragm moves the spring and valve stem to 50 percent operating range.

For on /off control of the valve, a solenoid is used to actuate the valve to a fully closed or fully open position. Applying current to the coil generates a magnetic field that moves the plunger downward against the return spring. With zero current applied to the coil the spring pulls the plunger upwards to the fully open position for a normally open state control valve.

Another method for variable valve positioning uses a motor and is referred to as proportional control mode. Using a gear motor attached to the valve stem a servo amplifier provides a DC control signal that moves the valve to the desired position. Feedback is achieved with the wiper arm attached to the valve stem that sends a signal back to the servo amplifier where the position is monitored the servo amplifier drives the motor until the control signal is equal to the feedback signal.

Watch the video below for an illustrated explanation. For more information on control valves, contact Ives Equipment at 877-768-1600 or visit http://www.ivesequipment.com.

Valve Actuators: An Overview

Rack & Pinion Actuated Valve
Rack & Pinion Actuated Valve
(courtesy of Flowserve Worcester)
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.
Electric Valve Actuator
Electric Valve Actuator
(courtesy of Flowserve Worcester)

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.

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.

Manual valve
Manual  cryogenic ball valve
(courtesy of Flowserve Worcester)
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.

Contact Ives Equipment with any valve automation requirement you may have.

Step-by-Step Instructions for Installing a Samson 3277 Actuator

The Samson 3277 is a pneumatic linear actuator suitable for attachment to Samson Series 240, 250, 280 and 290 control valves, as well as the type 3510 Micro-flow valves. Designed with a rolling diaphragm and internal springs, the Samson 3277 is popular because of its low overall height, fast response, low friction, and its ease to maintain. Attaching the actuator, or replacing one, can be done in minutes, without the need of special tools.


This video provide step-by-step instruction on how to install the 3277 actuator.