Buying guide to “External balance screw type thermodynamic expansion valve ”
The item is available for retail and wholesale;
The place of origin is in China,when you buy one or two,please consider freight(by air or by sea) into the cost;
Accept bulk order with Container delivery;
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General Knowledge on “External balance screw type thermodynamic expansion valve ”
External balance screw type thermodynamic expansion valve is shown in Figure 4-26. It is basically similar to the internal balance expansion valve. There are four main differences:
Figure 4-26 Shape of the externally balanced thermal expansion valve
(1) The pressure generated under the diaphragm is different.
The diaphragm is not in contact with the supplied liquid, but has a cavity connected to the evaporator outlet by a balance tube to directly introduce the superheated vapor pressure at the outlet end of the evaporator into the lower portion of the expansion valve diaphragm.
(2) The form of the adjustment lever is different. The installation of the externally balanced thermal expansion valve is shown in Figure 4-27. It is connected to the evaporator through a liquid separator. The temperature sensing package is placed on the outlet pipe of the evaporator to sense the superheat of the evaporator.
Turn left |turn right
Figure 4-27 Installation position of the externally balanced thermal expansion valve
(3) the flow of the external balanced thermal expansion valve is large, so the valve core adopts the conical structure instead of the valve needle.
(4) the temperature sensing bag of the external balance thermal expansion valve is filled with adsorbent (activated carbon or silica gel) and filled with carbon dioxide gas. It is used to absorb carbon dioxide gas, improve the working performance of expansion valve, so that the pressure in the bellows only changes with the temperature in the temperature sensing bag, but has nothing to do with the ambient temperature of bellows and capillary. The external flat type thermal expansion valve improves the working conditions of the evaporator. But its structure is more complex, manufacturing and installation are more difficult, so it is only used when the pressure loss of the evaporator is large.
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