Pressure reducing valve and regulating valve difference

Regulating valve Regulating valve used to regulate the flow of media, pressure and level. According to adjust the position of the signal, the valve automatically control the opening, so as to achieve the media flow, pressure and liquid level adjustment. Regulating valve sub-electric control valve, pneumatic control valve and HYDRAULIC CONTROL VALVE. This manual mainly introduces two kinds of electric control valve and pneumatic control valve. Regulating valve by the electric actuator or pneumatic actuator and control valve of two parts. Regulated and usually divided into two types of direct-through single-seat and direct two-seat, the latter has the ability to circulate large, uneven and small operation stability characteristics, it is generally particularly suitable for large flow, high pressure drop and leakage less occasions. Flow capacity Cv is one of the main parameters to select the control valve, the control valve flow capacity is defined as: When the control valve is fully open, the pressure drop across the valve is 0.1MPa, the fluid density of 1g / cm3 hourly flow path The number of flow control valve, known as the flow capacity, also known as flow coefficient, in Cv, said t / h, liquid Cv value calculated according to the following formula. According to the size of flow capacity Cv check the table, you can determine the nominal valve DN. Flow characteristics of the control valve, the pressure drop at both ends of the valve to maintain a constant condition, the medium flow through the control valve and the relative flow of its relationship between the opening. Regulating valve flow characteristics of linear characteristics, such as percentage characteristics and parabolic characteristics of three. The significance of the three kinds of fluency features are as follows: (1) Equal Percentage Characteristics (Logarithmic) The relative and relative flow rates of equal percentage characteristics do not have a linear relationship, and the change of the flow rate caused by the unit stroke change at each point of the stroke corresponds to this point Of the traffic is proportional to the percentage of traffic changes are equal. So it has the advantage of small flow, small changes in traffic, traffic flow, the flow changes, that is, in different degrees, with the same regulation accuracy. (2) Linearity (Linearity) Relativeness and linearity of linearity are linear. Changes in unit stroke caused by changes in the flow is unchanged. When the flow rate is large, the relative value of the flow rate changes little, and when the flow rate is small, the relative value of the flow rate changes greatly. Regulating VALVES, including regulating valve, throttle and Pressure Reducing Valve, its role is to regulate the media pressure, flow and other parameters. According to the structure of the control valve is divided into nine categories: (1) single-seat control valve; (2) two-seat control valve; (3) sleeve regulating valve; (4) angle control valve; (6) diaphragm valve (7) BUTTERFLY VALVE (8) ball valve (9) Eccentric rotary valve. The first six kinds of straight stroke, the latter three kinds of angular travel. Control valve, used to regulate the flow of media, pressure and liquid level. According to adjust the position of the signal, the valve automatically control the opening, so as to achieve the media flow, pressure and liquid level adjustment. Regulating valve by the electric actuator or pneumatic actuator and control valve of two parts. Regulated and usually divided into two types of direct-through single-seat and direct two-seat, the latter has the ability to circulate large, uneven and small operation stability characteristics, it is generally particularly suitable for large flow, high pressure drop and leakage less occasions. The valve is a control component in the fluid delivery system with functions such as cut-off, regulation, flow diversion, counterflow prevention, voltage regulation, shunt or overflow relief. Valves for fluid control systems, ranging from the simplest shut-off valves to the very wide range of valves used in the most versatile automation systems, come in a wide range of variants and sizes. Valves can be used to control the flow of various types of fluids such as air, water, steam, corrosive media, slurries, oils, liquid metals and radioactive media. Nominal valve through a few mm from the gauge needle valve to 10m of industrial piping valves. The working pressure of the valve can be extra high pressure from 1.3 × 10-3MPa to 1000MPa. Operating temperature from -269 ℃ ultra-low temperature to 1430 ℃ high temperature. Valve opening and closing can adopt a variety of control methods, such as manual, pneumatic, electric, hydraulic, electro-gas or electro-hydraulic linkage and electromagnetic drive, etc .; also in the pressure, temperature or other forms of sensing signal, According to the requirements of the scheduled action, or only a simple open or closed. Electric control valve is a power-driven, to accept a unified standard electrical signal 0-10mA (or 4-20mA), amplified by the servo amplifier, the motor drive reducer operation resulting in axial thrust to adjust the spool corresponding shift , To achieve the process of media flow, pressure, temperature, liquid level and other variables to adjust the intelligent control valve. Electric control valve by the electric actuator and the control valve is composed of two parts, divided into direct-pass single-seat and direct two-seater two, which has the ability to circulate large, unbalanced force is small and stable operation, it is usually particularly suitable for Large flow, high pressure drop and leak less occasions. The flow characteristics of the electric control valve is the relationship between the relative flow of the medium through the control valve and its opening under the condition that the pressure difference between the two ends of the valve is kept constant. Electric flow control valve features a linear flow characteristics, such as percentage characteristics and parabolic characteristics of three. The meaning of the three flow characteristics is as follows: (1) Equal Percentage Characteristics (Logarithm) Equal Percentage Characteristics The relative and relative flow rates do not have a straight line relationship, and the change of the flow rate caused by the unit stroke change at each point The flow is proportional to the percentage change in flow is equal. So it has the advantage of small flow, small changes in traffic, traffic flow, the flow changes, that is, in different degrees, with the same regulation accuracy. (2) Linearity (Linearity) Relativeness and linearity of linearity are linear. Changes in unit stroke caused by changes in the flow is unchanged. When the flow rate is large, the relative value of the flow rate changes little, and when the flow rate is small, the relative value of the flow rate changes greatly. (3) Parabolic characteristics The flow rate varies in proportion to the two sides of the travel, and generally has the intermediate characteristics of the linear and equal percentage characteristics. From the analysis of the above three characteristics can be seen, in terms of its regulatory performance, with equal percentage characteristics for the best, stable regulation, good regulation performance. The parabolic characteristics than the linear characteristics of the regulatory performance is good, according to the different requirements of the occasion, select any one of the flow characteristics. Regulating valve is a series of control valves, the main role is to adjust the medium pressure, flow, temperature and so on parameters, Is the ultimate control element in the process loop. Regulating valve can be divided according to travel characteristics: Straight travel and angular travel. Straight stroke includes: single-seat valve, double-seat valve, sleeve valve, angle valve, three-way valve, diaphragm valve; Angle stroke include: butterfly valve, ball valve, eccentric rotary valve, full-featured ultra-light control valve. Regulating valve by driving mode can be divided into: pneumatic control valve, electric control valve and Hydraulic Control Valve; By adjusting the form can be divided into: regulation, cut off, adjust the cut off; According to the flow characteristics can be divided into: linear, equal percentage Parabolic, quick opening. Regulating valve for air, water, steam, all kinds of corrosive media, mud, oil and other media. Regulator valve is the use of control valve body opening and closing pieces of the opening to regulate the media flow, the media pressure is reduced, while the role of the valve with the pressure regulator opening and closing pieces of the opening, the valve pressure to maintain Within a certain range, and in the valve body or after the injection of cooling water, the medium temperature decreases, this valve is called decompression valve. The characteristic of this valve is to keep the outlet hearing pressure and temperature within a certain range under the condition that the inlet pressure is constantly changing. Smart valves that use media's own energy to regulate and control line pressure. For domestic water supply, fire water supply and other industrial water supply system, through the control valve decompression pilot valve, you can adjust the outlet pressure of the main valve. Export pressure does not change due to changes in inlet pressure and inlet flow. Export pressure is safely and reliably maintained at the set point, and the set value can be adjusted to achieve the purpose of reducing pressure as needed. The valve decompression precision, stable performance, safe, reliable, easy installation and adjustment, long service life. Reducing valve for water, steam, air medium pipeline, by adjusting the inlet pressure to a desired outlet pressure, when the inlet pressure and flow changes, by the media itself automatically maintain the outlet pressure within a certain range , But the difference between inlet pressure and outlet pressure must be ≥0.2 MPA / CM. Pressure Relief Valve classification according to the structure can be divided into film, spring film, piston, lever and bellows; according to the number of seats can be single-seat and two-seat; according to the location of the valve can be divided into Positive and negative. Pressure relief valve installation and maintenance should note the following: For ease of operation and maintenance, the valve is generally mounted upright on the horizontal pipe. Installation should be taken to ensure that the flow of medium in the pipeline and valve resting on the direction of the arrow shown. In order to prevent pressure overpressure after the valve, a relief valve should be installed at not less than 4M from the valve outlet.