water pressure regulator

I assume that you live in a high rising buliding. In Hongkong water supply for floors below 6th floor are supplied directly from the water supply. Water supply for high floors are coming from the water storage tank found on the roof top.

When water is supplied from the storage tank, there is static pressure at the point of tapping. The static pressure is resulting from the head of the water. It equals to 1 bar for every 10m of water head. For example, every floor is 3.0 m head room, and there are 30 floors. We can approximate the storage tank is at a height of 30 x 3.0 m = 90 m from the ground. You live at 11 floor, and water is tapping from the storage tank. There is a elevation of 90 m - 11 x 3 m = 57 m from you flat to the storage tank. It implies that when the water tap is closed (it is static), there is always a static pressure of 5.7 bar at the water pipe that goes into your apartment. It is too high for the components within the water system inside your home. That is the reason a water pressure regulator is needed to reduce the pressure.

Water hammer is another important consideration. When a water tap is opened, water runs out smoothly. When the tap is closed slowly, the water flows slowly and eventually stopped when the water is closed. It creates no water hammer or sudden fluid pressure surge back in the supply line. However, there are occasions that the water tap is closed suddenly. In such a case the flowing water stopped suddenly. It creates "water hammer" inside the supply piping. Because water hammer is a sudden pressure surge, most of the normal piping cannot stand such a high pressure.

The above describes a scenario of a water supply system at a flat within a high rising building. In order to determine whether the pressure regulator at your flat can be removed, the whole water supply system must be evaulated.

In the case that it is difficult to evaluate the water system, I suggest conneting the water filter with flexible piping instead of regular steel / copper pipe. Flexible piping allows the filter to be installed not in the same line (offset) with the supply pipe.