Pump and Expansion Tank

The second big part of Thermaltake PW 850i ProWater liquid-cooling system is the pump and expansion tank block:

These two irreplaceable parts of any liquid-cooling system are combined into a single block by Thermaltake PW 850i ProWater. The 350ml expansion tank is made of thick semi-transparent plastic. There are “Min” and “Max” marks for the coolant level on one of its sides. The filling hole at the top of the tank is covered with a screw-cap:

Two fittings also covered with protective rubber caps come out of the pump and tank:

Thermaltake PW 850i ProWater uses P501 pump (Thermaltake BigWater 760i uses P500 model):

However, they have pretty identical specs: water flow of 500 (±50) l/h, water lift of ~1.8m and power consumption of ~7.2W. According to the specifications, the claimed noise of the this pump is 16dBA and its ceramic bearing should last for 80,000 hours or more than 9 years of non-stop operation.

There are soft rubber pads stuck to the bottom of the expansion tank and pump:

They should be absorbing vibrations during work and thus reducing the level of generated noise.