Comparison Metabo HWW 4500/25 Inox vs Metabo HWW 4500/25 Inox Plus

The noise level produced by the pump during normal operation. For comparison, 50 decibels roughly corresponds to the noise in an office room, 60 dB to an average TV volume, 70 dB to a truck at a distance of about 8 m, 80 dB to traffic noise, and 90 dB to a scream. The lower the noise level, the more comfortable the use of the pump and the closer it can be placed to people. This parameter is especially important for models designed for indoor installation.

The material of the water pressure tank provided in the design of the pumping station.

Recall that the classic (not sewer) pumping station is a surface pump, supplemented by a water pressure tank. Such a tank is a reservoir where water accumulates. It performs two functions: it smooths out pressure drops in the system and stores some water in case the pump is turned off. For the main body in such containers, the following materials can be used:

— Cast iron. The simplest and most inexpensive option: cast iron is somewhat inferior to stainless steel in terms of strength and corrosion resistance. However, for those models in which it is used, these moments do not have a noticeable meaning.

— Stainless steel. The most advanced material in use: stainless steel combines high strength and corrosion resistance. However, such tanks are somewhat more expensive than other varieties.

— Steel. Non-stainless steel accumulators usually use special coatings to protect against corrosion. This material is superior to cast iron in strength and is somewhat cheaper than stainless steel.

— Aluminium. The main advantage of aluminium alloys is their light weight combined with quite decent strength and rust resistance. Of the shortcomings, a rather high price can be noted.