BWT STANDARD Installations- Und Anwendungshandbuch Seite 29

1. PURPOSE OF THE PRODUCT
Inside the membrane, water is separated into two streams: concentrate, which is discharged into
drain, and permeate, which enters pressure tank 2 for storage. The tank is connected to the output
through the membrane auto shut-off valve and check valve built into the transition fitting that is
installed in the permeate outlet of membrane housing. After the auto shut-off valve is installed the
union tee, through which the tank is connected to the filter rack with the yellow tube. On the top of
the tank, tank valve 6 is installed.
Pressure tank of the system accumulates purified water. Without it, reverse osmosis membrane
wouldn't be able to produce sufficient flow for direct water consumption. For example, if the filter
had an installed membrane with a performance of 50 GPD (7.9 L / h), it would take over 1.5 min to fill
the glass of 200 ml or 2 min for the 9 oz glass. Thus, the system stores purified water in the tank and
delivers it to the user as needed, and then generates a supply of water. Time required to fill empty tank
can range from 1.5 to 3 hours. After the tank has been filled the auto shut-off valve shuts off the water
supply from the pre-filters and the unit stops. After opening purified water faucet 3, the pressure of
water in the tank lowers, and the auto shut-off valve automatically resumes the flow of water through
the pre-filter cartridges to the membrane to re-fill pressure tank. Water with retained impurities (con-
centrate) is discharged into drain through the concentrate outlet, connected with black tube to drain
saddle 8, which is installed on drain pipe. In order to create backpressure, which is required to main-
tain the operating pressure inside the membrane housing, flow restrictor 14 is installed in the black
tube. Flow restrictor is a plastic insert with precision bore capillary. The flow restrictor is inserted inside
the end of black tube that is fitted in the membrane concentrate outlet.
When drawn from the faucet, purified water runs from the pressure tank through the union
tee through to the fifth stage of purification—carbon post-filter, intended for the final purification
of water. It contains high quality activated carbon made from coconut shell. This filter improves
and refines flavor of purified water. Carbon post-filter is connected with blue tube to the drinking
water faucet 3 mounted on sink or counter.
Code P0090636 - Rev 0 - 19/06/2019
29