Thanks to a magnificient hydraulic balancing, an efficient operation is ensured where more than one or cooling group is used or in multi-pump systems. As well as hydraulic balance, it is very important to separate the air and residue in the system. Hydraulic balance and air separation could be ensured with a single product. Thus, four installation connection will be enough instead of eight. Advantage is gained in respect of both first investment and installation and workmanship costs.