Pneumatic actuators Pneumatic actuators utilize an air signal from an external control device to create a control action via a solenoid. These are commonly available in two main forms Piston actuators Diaphragm actuators Piston actuators Piston actuators are generally used where the stroke of a diaphragm actuator would be too short or the thrust is too small. The compressed air is applied to a solid piston contained within a solid cylinder. Piston actuators can be single acting or double acting, can withstand higher input pressures, and can offer smaller cylinder volumes which can act at high speed. Diaphragm actuators Diaphragm actuators have compressed air applied to a flexible membrane called the diaphragm. These types of actuators are single acting, in that air is only supplied to one side of the diaphragm, and they can be either direct acting (spring-to-retract) or reverse acting (spring-to-extend).  Advantages of Pneumatic Actuators The biggest advantage of the pneumatic actuat

  Actuators   A valve actuator is a device that produces force to open or close the valve utilizing a power source. This source of power can be manual (hand, gear, chain-wheel, lever, etc.) or can be electric, hydraulic or pneumatic. Basic actuators turn valves to either fully opened or fully closed positions. But modern actuators have much more advanced capabilities. They not only act as devices for opening  and closing valves, but also provide intermediate position with high degree of accuracy. The valve actuator can be packaged together with logic control and digital communication ability to allow remote operation as well as allowing predictive maintenance data. Type of Actuators   Pneumatic actuator Electric actuator Pneumatic actuator Pneumatic actuators utilize an air signal from an external control device to create a control action via a solenoid. These are commonly available in two main forms Piston actuators Diaphragm actuators. Electric actuator Electric actuators are motor d

  Gate Valves Gate valves use linear type of stem motion for opening and closing of a valve. These valves use parallel or wedge shaped discs as closure members that provide tight sealing. Gate valves are a common valve type used for basic on/off service. Manual Gate Valves are operated with a simple hand wheel that causes the stem and gate to rise. When closed, the gate seats against a seat ring, both of which have a special treatment to provide reliable shut-off. Advantages High capacity  Tight shutoff  Low cost  Little resistance to flow  Ability to cut through slurries, scale and surface build-ups Provide unobstructed flow paths that not only provide high flow capacity (Cv), but  even allows slurry, large objects, rocks and items routinely found in mining processes to safely pass through the valve.  Disadvantages Poor control  Cavitate at low pressure drops  Cannot be used for throttling Relatively low pressure limitation - general pressure limitations are 150 psi at maximum.  Uses

 Globe Valves Globe valves consist of a movable disk-type element and a stationary ring seat in a generally spherical body. The valve stem moves a globe plug relative to the valve seat. The globe plug can be at any position between fully opened and fully closed to control flow through the valve. The globe and seat construction gives the valve good flow regulation characteristics. Turbulent flow past the seat and plug, when the valve is open, results in a relatively high pressure drop, limited flow capacity, and low recovery. Advantages Efficient and precise throttling  Accurate flow control  Disadvantages Low recovery and relatively low coefficient of flow (Cv).  High pressure drop, higher pump capacity and system wear  More expensive than other valves The sealing device is a plug that offers limited shut-off capabilities, not always meeting bubble tight requirements. Applications requiring Precise flow regulation Frequent and wide throttling operation  Suited to very high pressure dro

  Control Of Air To Fuel Ratio The fuel/air ratio is the lowest if excess air level (measure in percent of oxygen 02) is present in the flue gas at a set firing rate without the carbon monoxide (CO) being produced. At low firing rates; the burner design requires more excess air to ensure the mixing of air with the fuel in proper ratio. At higher firing rates there is enough differential pressure drop (burner wind box to combustion chamber area) for the air to mix with the fuel. All boilers have a fuel/air ratio curve and it is extremely important that the plant has this documented information. In other words ratio control is adopted to maintain the air fuel ratio. The air to fuel ratio is the proportion of air to fuel supplied during combustion process. The optimal ratio (the stoichiometric ratio) occurs when all the fuel and oxygen in the reaction chamber balance each other perfectly. Rich burning occurs when there is more fuel than air in the combustion chamber while lean burning occ

  Five-layer IoT Architecture Another architecture which is five-layers IoT architecture is proposed by the researchers who were worked on IoT. In this five-layer IoT architecture, the three-layers which are the application, network, and perception layers are having same architecture like three-layer IoT architecture. Additionally, the Business layer, Transport layer, and processing layer are the new one. Business Layer Application Layer Processing Layer Transport Layer Perception Layer Business Layer: This layer is the head of the IoT architecture. It manages the complete IoT system even applications, user’s privacy, profit models, etc. Application Layer: This layer is to deliver the specific application to the end-user. The specific applications can be done with this application layer. Example of this layer like a smartphone, smartwatch,  smart TV, etc. which is used for a specific application. Processing Layer: It is in the middle of the IoT architecture. It’s having an important ro

  IoT Protocol Architecture The most interesting point here is, IoT has don’t have any particular architecture. The researchers proposed different IoT architectures. But in that most proposed architectures three-layer architectures & five-layer architecture. Three-layer IoT Architecture This architecture introduced in the early days of research of IoT technology. The three-layers are in IoT architecture is for Application Layer Network Layer Perception Layer Application Layer: This layer is to deliver the specific application to the end-user. The specific applications can be done with this application layer. Example of this layer like a smartphone, smartwatch,  smart TV, etc. which is used for a specific application. Network Layer: Network layer have an important role in IoT architecture. It connects to the other smart electronic devices (smartwatches, servers, etc). The network layer is for transmitting and processing the sensor data. Perception Layer: It is the physical layer and

  What is wireless charging? Wireless charging is a technology that charges devices without using connectors or metal contacts. This is also referred to as non-contact charging, non-contact power transmission, and wireless power supply. Wireless charging technology is attracting increased attention by eliminating the need for power cords when charging. This is expected to increase connector safety and resistance to dust and water while enabling multiple devices to be charged using a single charger.

  Simple Low cost DC Motor Project 

  Butterfly Valves Butterfly valves consist of a disc attached to a shaft with bearings used to facilitate rotation. These are considered high recovery valves, since only the disc obstructs the valve flow path. The flow capacity is relatively high and the pressure drop across the valve is relatively low. The butterfly valves are used for limited throttling where a tight shut off is not required. When fully open, the butterfly creates little turbulence or resistance to flow. Best Suited Control Linear Equal percentage  Recommended Uses Fully open/closed or throttling services Frequent operation Minimal fluid trapping in line Applications where small pressure drop is desired  Applicable Standards AWWA C504 for rubber-seated butterfly valves API 609 for lug and wafer type butterfly valves MSS SP-69 for general butterfly valves UL 1091 for safety butterfly valves for fire protection services  Advantages Low cost and maintenance High capacity  Good flow control Low pressure drop  Disadvanta

  What Is A Circuit? An electronic circuit is a circular path of conductors by which electric current can flow.  A closed circuit is like a circle because it starts and ends at the same point forming a complete loop. Furthermore, a closed circuit allows electricity to flow from the (+) power to the (-) ground uninterrupted. In contrast, if there is any break in the flow of electricity, this is known as an open circuit.

  Ball Valves Ball valves are a quick opening valves that give a tight shutoff. When fully open, a ball valve creates little turbulence or resistance to flow. The valve stem rotates a ball which contains an opening. The ball opening can be positioned in the fully open or fully closed position but must not be used to throttle flow as any abrasive wear to the ball will cause leakage when the valve is closed. Ball valves are considered high recovery valves, having a low pressure drop and relatively high flow capacity. Best Suited Control Quick opening Linear Recommended Uses Fully open/closed, limited-throttling Higher temperature fluids  Advantages Low cost  High flow capacity  High pressure/temperature capabilities Low leakage and maintenance  Tight sealing with low torque Easy quarter turn operation- desirable to most operators Fairly easy to automate.  Disadvantages Limited throttling characteristics  Prone to cavitation  Not suitable for slurry applications due to cavities around the

  Low cost LDR sensor project without using Arduino  

  Top 40 Digital Signal Processing Objective Questions and Answers 1. DTFT is the representation of a) Periodic Discrete time signals b) Aperiodic Discrete time signals c) Aperiodic continuous signals d) Periodic continuous signals Answer: Aperiodic Discrete time signals 2. The interface between an analog signal and a digital processor is a) D/A converter b) A/D converter c) Modulator d) Demodulator Answer: A/D converter 3. The speech signal is obtained after a) Analog to digital conversion b) Digital to analog conversion c) Modulation d) Quantization Answer: Digital to analog conversion 4. x(n)=x(n-1)/4 with initial condition x(0)-1, gives the sequence a) x(n)= (1/4)^n b) x(n)= -(1/4)^n c) x(n)= (1/4)^-n d) x(n)= (-1/4)^-n Answer: x(n)= -(1/4)^n 5. For a system function H(s) to be stable a) The zeros lie in left half of the s plane b) The zeros lie in right half of the s plane c) The poles lie in left half of the s plane d) The poles lie in right half of the s plane Answer: The poles

  Direct and Pilot Actuated In the direct-actuated type, the power unit (bellows, diaphragm, and so on) of the thermal actuator is directly connected to the valve plug and develops the force and travel necessary to fully open and close the valve. Direct-actuated regulators are generally simpler, lower in cost, and more truly proportional in action (with somewhat better stability). In the pilot-actuated design, the thermal actuator moves a pilot valve, internal or external. This pilot controls the amount of pressure energy from the control agent (fluid through valve) to a piston or diaphragm, which in turn develops power and thrust to position the main valve plug. The pilot may be internal or external. When external, independently acting multiple pilots are also available. Compared to direct-actuated TCVs, pilot-actuated regulators have smaller bulbs, faster response, and narrower proportional band, and they can handle higher pressures through the valve. Pilot-actuated regulators can al