The foremost theory on control valves and instrumentation

-


Generally, valves are devices that regulates and control the flow of a fluid either by partially opening,fully opening or closing of the valve disc.
Control valves which is the focus are valves that regulates the flow of fluid through the signals as directed from the sensors.Control valves can either be operated through electrical, pnuematic or hydraulic actuators.
Control valves are classified according to;


  • Action; air to open and air to close
  • Flow characteristics; ideal characteristics and installed or effective characteristics
  • Numbers of plugs; single seating plug and double seating plug


Based on Action
These are controls valves which are operated through pneumatic actuators to fully open or close the valve when air supply fails based on the need of the process.
https://instrumentationtools.com/wp-content/uploads/2016/10/instrumentationtools.com_control-valve-operation.png

Based on flow characteristics
This shows the relationship between the control valve capacity and the movement of the stem. The ideal characteristics shows the relationship with constant pressure drop across the control valve while the effective characteristics show the overall pressure drop across the various installed valves in the process. Its also determined by the shape and size of the valve plug.

 https://instrumentationtools.com/wp-content/uploads/2016/10/instrumentationtools.com_control-valve-plug-shapes.png

Based on numbers of plug
The numbers of plugs present determines the flow rate of the process. A single seating plug allows flow in one direction and it recommended for shut off system while the double seating plug allows flow in double direction through the upward and downward movement of the two plugs via the stem. The double seating plug is not suitable for a shutoff system due to the differential temperature expansion of the stem and the valve seat, however in a process that doesn't need a shutoff system, the double seating valve can be installed.


https://instrumentationtools.com/wp-content/uploads/2016/10/instrumentationtools.com_single-seated-and-double-seated-control-valves.png


  •      Solenoid valve


   The solenoid valve which is a commonly used valve in the regulating of fluid,  is an electromechanically operated device that is controlled by current through a solenoid. The valve consists of a solenoid and a moveable ferromagnetic core.  The ferromagnetic core closes off the orifice when the circuit is opened. An electric current passes through the coil when the circuit is closed, hence causes a magnetic field to be created. The magnetic field generated exerts force on the core hence cause it to push towards the centre of the coil so that the orifice can be opened.

http://www.hvacspecialists.info/wp-content/uploads/2011/01/solenoid-valve-diagram.jpg

Comments

Post a Comment

Popular posts from this blog

THE FUNDAMENTALS OF THE TWO STROKE CYCLE ENGINE

-
Image
There are uncertainty about the longevity of the two stroke cycle engine as compared to other cycle of operation .Knowledge of Its importance and principles of operation will help justify the strength of the two stroke cycle engine as compared to others.  Internal combustion engine dated back to 1876 when Dr. Nicolaus A. Otto first invented the spark ignition engine[petrol], then Rudolf Christain Karl Diesel developed the compression ignition engine[Diesel]. Since then engines have continue to develop with new technologies as well as increase in the knowledge of engine process. The purpose of the internal combustion engine is the production of mechanical power from chemical energy contained in fuel. The energy is released by burning the fuel inside the engine.  According to the cycle of operation,engines are classified as the two stroke cycle,four stroke cycle six stroke cycle and the rotary combustion. The rise in global technology which increased the demand of new type of engi
Read more

PETROL PUMPED INTO DIESEL TANK: WHAT SOLUTIONS ARE AVAILABLE?

-
Image
Fortunately you discovered you just pumped petrol instead of diesel into your compression ignition engine(Diesel engine). Oh my! the knowledge they burn completely different(volatile versus high flash point) must give you a lot to worry about. Don't panic too much, there's are ways to get over it. Filling a fuel tank is a simple task, but seconds of carelessness might result to some expensive nuisance. Possibly you might be a newbie to compression ignition engine(C.I engines) or maybe a veteran in the use of it or Probably you might be familiar to the C.I engine and the spark ignition engine,Good one. Herein this article, the anti and post caution will be highlighted. Petrol and Diesel in the fuel tank Early discovery of this nuisance will help reduce the cost of repair,that is towing immediately to he mechanical workshop for the petrol to be completely drained.  The worst case might be when the engine starts running with the fuel tank full of petrol--there are chance
Read more

THE BASICS OF THE COMPRESSION IGNITION ENGINE

-
Image
The compression ignition engine[C.I engines] also known as the diesel engine is invented by Dr. Rodolph Diesel. The C.I engine is an internal combustion engine in which combustion occurs as a result of the compression of the air to a temperature sufficient enough to ignite the fuel. There are several similarities and minor difference between the C.I engines and the gasoline powered engines(spark ignition engines,S.I engines). The components such as the crankshaft, camshaft, piston,valves etc they both share in common.  The same cycle of operation governs both for the four stroke and two stroke engine process. However the diesel engines can easily be recognized by the absence of the ignition system and other factors such as Injection of fuel is done via an injection pump They are noisy and produces pollutants easily It produces more power and torque Overtime, diesel engines have received massive success in the construction of heavy duty trucks,construction equipment ,power pl
Read more

Career choice 2: why MECHATRONICS ENGINEERING

-
Image
Technology has been effective in the production and construction of machineries of which have upgraded the standard of living globally. This rise in technology has made complex jobs easier, and comfort of mankind enhanced through the use of smart systems/device. Devices like the fuel injection system, anti-lock braking system where software applied to control mechanism has produced a more powerful, dynamic and efficient behaviour of the vehicle when accelerating or decelerating. The industrial robots, machine tools, aircraft flight control and navigation system, washing machines and dryers have helped the standard of living. These devices are produced by the MECHATRONICS ENGINEERS. MECHATRONICS ENGINEERING The engineering technology called "mechatronics" was invented by Tetsuro mori who was a senior engineer at the yaskawa electrical corporation in 1969. In 1971,  the word mechatronics was registered as a trademark by the company in Japan with the registration number 4
Read more

THE TURBOCHARGER SERIES

-
Image
The value of the turbo charger in an automobile is unknown to a few engineers and its users, because they lack the proper knowledge on these points of the component itself. http://d3e98kcom2u4ch.cloudfront.net/wp-content/uploads/oldblog/2016/09/turbocharger-operation-diagram.jpg What is the value of the turbocharger? What is it made of? How does it work? Where can it applied? Likely problem encountered Ignorantly we think the main reason motor A generates more power,higher velocity,consumes less fuel, sometimes environmental friendly than motor B is because of the engine structure or size. But there is one way to improve an engine which is the turbocharger. The turbocharger is an exhaust-gas driven component of an engine that increases the volumetric efficiency of air in an engine in order to increase its power.  It consist of a casing,impellers and shaft. Generally, the charge[mixture of fuel and air] that flows into the combustion chamber produces the torqu
Read more

Career choice(why MECHANICAL ENGINEERING)

-
Image
Mechanical engineering is a branch of engineering that uses creative abilities and knowledge to design, analyse, manufacture and maintain mechanical system through the application of physics, material science and engineering principles. Mechanical engineering is known as the structure of engineering because of its ability to understand, predict and calculate the stability, rigidity and the strength(plasticity, elasticity,  toughness, hardness) of materials used in construction of a structure. Branches of Mechanical Engineering This field of engineering consist of various branches due to it complex form. Some of the branches are Vehicle engineering: This branch of engineering consist of automobile engineering,  aerospace engineering and marine engineering. Manufacturing engineering: it focuses on the application of engineering procedures in manufacturing processes and production method to improve quality of the product. The procedures consists of robotics, computer network,
Read more

THE MAIN FACTORS BEHIND LOSS OF POWER IN AN ENGINE

-
Image
Most operators lacks the proper knowledge on how to use and maintain an engine. Knowing the requirements for an engine to produce power and other function are important factors that must be learned in engine maintenance.   Humans are mostly ignorant of the sign of power loss that emanate from the engine even when they are sometimes pronounced. For an engine to produce or loss power there are four factors that must be consider AIR FUEL COMPRESSION SPARK PLUG AIR Generally, in the absent of air, combustion of fuel can not occur. The mixture of air and fuel, known as the charge is a major factor for an engine to produce power,in absential power can not be generated. Air contains dust,dirt particles and other contaminants of which if drawn into the injector, it causes blockage of  the injector nozzle and the running jet of the carburetor. in cases like this, the air filter is applied to prevent the dirt and contaminant from flowing through to the mixing chamber. The air
Read more

CONSTRUCTION PROCEDURES OF AN OFFICE CHAIR

-
Image
The construction procedures of an executive office chair are stated below Selection of materials Engineering drawing/sketches Measuring and marking out dimension Cutting operations Drilling operations Formation of shapes Joining operations Upholstery Surface finishing SELECTION OF WORKING MATERIALS This involves the consideration of the best materials for the construction of the chair. Materials such as galvanized mild steel pipe, mild steel rod, mild steel plate,  leathers, foam, rubber hose, electrode, paint, screw nut,  bolt and adhesive. ENGINEERING DRAWING/SKETCHES Engineering drawing is the first thing to do when constructing the executive office chair, it gives the graphical conception of the chair. It helps to remain focus on the ideal chair to be constructed. MEASURING AND MARKING OUT This involves the use of vernier calliper and measuring tape to take a precise dimension of the work piece. Tools like scriber and talc are also used to mark out the measure
Read more

ROBOTIC FISH makes discovery safer underwater

-
Image
The 21st century scientists are working extremely hard to make life easier for humans.  The invention of domestic and industrial robots and other devices makes the work done efficient,  though it threatens welfare of humans. Scientists have developed robotic fish to help researchers do underwater research. The robo-fish can swim alongside real fish to give new perception into life below. The robotic fish named SoFi was developed by MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL), can be controlled with sound. SoFi swims by flapping its hydraulic-pump powered tail back and forth.  The clever robot can also control its own buoyancy through adjusting an internal foam material. During test dives in the Rainbow Reef in Fiji, SoFi was able to swim down 15 meters for more than 0 minutes at a time. It could navigate and respond to current and avoid collision with coral. During the swim, SoFi collected data by taking photos and videos using its b
Read more

5 AMATEUR MECHANICS WHO TURNED THEIR CAR INTO WORK OF ART

-
Image
1. The Carthedral: A Cathedral on Wheels Built from a hearse and topped with a VW Bug, Rebecca Caldwell's Carthedral is an ambitious gothic car art piece. The piece is entirely street legal, and features spires, buttresses, and other gothic flourishes you'd expect to find in a several-centuries-old church. 2. The Phantom Built by Truant Studios' William T. Burge,  The Phantom  began with only a VW motor, an axle, suspension and steering. Burge built the entire body from scratch, welding small pieces of steel together to create the car's iconic look. It features three imposing gargoyle heads, and its design is based on that of a 1936 Bugatti Atlantic. 3. Thor: The Norse God of Cars Built in Denver, Colorado, the  Thor art car  started as a Burning Man mutant vehicle project. Since its debut at the festival, it has traveled the world. The double-decker vehicle is a mobile party space, with lightweight metal framing providing the basis
Read more