The element charge (i.e., the fluid in the power element of a TX valve) is usually one of three types:
1. GAS CHARGE
2. LIQUID CHARGE
3. CROSS CHARGE
CROSS CHARGES use a refrigerant in the thermostatic element that is different from the refrigerant used in the refrigeration system. By using a different refrigerant, the relationship between the forces due to the evaporator pressure and suction pressure can be modified. Cross charges are often introduced so that the bulb pressure does not rise as rapidly as the pressure of the refrigerant in the system.
Cross charges have advantages similar to those of gas charges (flood-back protection during shut-down and startup), and at the same time, they are suitable for low-temperature work. Cross charges also help to reduce hunting.
No comments:
Post a Comment