Industry News
Knowledge quickly exhaust valve exhaust valve works ---2009-10-29
According to process conditions, choose a suitable control valve structure and material
1, how to select the type of control valve
Before and after the pressure control valve smaller, require less leakage can typically choose a single seat valve;
Low dropout regulator, large flow of gas may make use of butterfly valve;
Strong corrosive fluids regulation may make use of diaphragm valves;
Not only want to regulate also requested the cut may make use of eccentric rotary valve;
Noisy when the optional sleeve valve.
2, how to select control valve materials
According to media, working pressure, temperature, corrosion, cavitation erosion is serious and so selection.
Generally cast to be elected;
When using the less demanding (+120 ¡æ, 1.6MPa or less) may also use cast iron;
High-temperature (450-600 ¡æ) or low temperature (-60-250 ¡æ) forum should be used 1Cr18Ni9Ti;
High Voltage (22-32MPa) occasions should be used forged steel, 1Cr18Ni9Ti, Cr18Ni12Mo2Ti;
Strong corrosive medium to be elected 1Cr18Ni9Ti;
Process control valve according to the characteristics of the object, select the appropriate flow characteristics of
Control valve flow characteristics are medium flow control valve relative flow and relative displacement (control valve relative opening) the relationship between the general control valve spool to change the flow cross-section with the valve seat, to control the flow. But in fact a variety of factors, such as the closure of area change, it is also occurring before and after the pressure valve of the change, while the changes in pressure in turn cause traffic changes.
Remain unchanged before and after the pressure in the valve, the control valve flow characteristic is called the ideal flow characteristics; the structural characteristics of control valve spool displacement refers to the cross-sectional area and fluid flow of the relationship between the size and spool it is purely geometric shapes decisions, and control the geometric shape of the valve, but also take into account in the case of constant pressure flow coefficient, therefore, the ideal flow control valve
1, from the conditioning system quality analysis
The following figure shows a heat exchanger with the automatic adjustment system, which is adjustable object, transmitters, instrumentation and control valves regulate the composition of such links.
K1 transmitter amplification factor, K2 regulation instrument amplification factor, K3 executive body of the amplification factor, K4 control valve of the amplification factor, K5 adjust the object magnification factor.
1, how to select the type of control valve
Before and after the pressure control valve smaller, require less leakage can typically choose a single seat valve;
Low dropout regulator, large flow of gas may make use of butterfly valve;
Strong corrosive fluids regulation may make use of diaphragm valves;
Not only want to regulate also requested the cut may make use of eccentric rotary valve;
Noisy when the optional sleeve valve.
2, how to select control valve materials
According to media, working pressure, temperature, corrosion, cavitation erosion is serious and so selection.
Generally cast to be elected;
When using the less demanding (+120 ¡æ, 1.6MPa or less) may also use cast iron;
High-temperature (450-600 ¡æ) or low temperature (-60-250 ¡æ) forum should be used 1Cr18Ni9Ti;
High Voltage (22-32MPa) occasions should be used forged steel, 1Cr18Ni9Ti, Cr18Ni12Mo2Ti;
Strong corrosive medium to be elected 1Cr18Ni9Ti;
Process control valve according to the characteristics of the object, select the appropriate flow characteristics of
Control valve flow characteristics are medium flow control valve relative flow and relative displacement (control valve relative opening) the relationship between the general control valve spool to change the flow cross-section with the valve seat, to control the flow. But in fact a variety of factors, such as the closure of area change, it is also occurring before and after the pressure valve of the change, while the changes in pressure in turn cause traffic changes.
Remain unchanged before and after the pressure in the valve, the control valve flow characteristic is called the ideal flow characteristics; the structural characteristics of control valve spool displacement refers to the cross-sectional area and fluid flow of the relationship between the size and spool it is purely geometric shapes decisions, and control the geometric shape of the valve, but also take into account in the case of constant pressure flow coefficient, therefore, the ideal flow control valve
1, from the conditioning system quality analysis
The following figure shows a heat exchanger with the automatic adjustment system, which is adjustable object, transmitters, instrumentation and control valves regulate the composition of such links.
K1 transmitter amplification factor, K2 regulation instrument amplification factor, K3 executive body of the amplification factor, K4 control valve of the amplification factor, K5 adjust the object magnification factor.
