N-form  

N = built-in pressure bypass valve 

N-form: Built-in bypass valve, when the pressure inside the heat sink is too high; the built-in pressure valve opens; the pressure can be released from the channel inside the heat sink. When the pressure bypass valve is needed, there is no need to connect the return pipeline; convenient and practical.

 W-form 

W = external pressure bypass valve 

W form: external pressure bypass valve, compared with the N form of the benefits are: the same specification of the fins do not have an internal leakage channel, the corresponding increase in the number of heat conduction fins; thus increasing the fin heat dissipation area. At the same time, the pressure relief effect of the external pressure bypass valve is also better than the internal leakage form. Note: When using the external bypass valve, it is necessary to connect an additional line back to the tank.

 M-form 

M = no bypass valve 

M form: No bypass valve, the same specification of the heat sink without internal leakage channel, the corresponding increase in the number of heat conduction fins; thus increasing the fin heat dissipation area. No external valve also do not need to connect an additional pipeline to connect back to the tank. However, it is necessary to make sure that the medium entering the cooler is low pressure without pulse pressure! Particularly suitable for independent circulation.