Nortec DRAABE Pure Water System - Manual (Page 19)

Created: 21.09.2006
Changed: 29.02.2008
Printed: 02.03.2009
page 19 of 59
3.2.4 Functional Description of Pressure Boost
The pressure boost system (DE) increases the output pressure of the pure water system
from the range 2-3 (29-44 psi) to the range 3-5 bar (44-73 psi).
The DE can be divided into two parts. The lower part is fixed to a wall and serves as an in-
terim storage tank. A float valve controls its inlet. If the interim tank is not completely full,
pure water can flow into it. When the maximum water level has been reached, the valve
turns the inlet off. The interim tank is equipped with a safety overflow and a drain plug.
inlet (pure water)
float valve
interim
storage tank
safety overflow
drain plug
Figure 8: Pressure Boost (lower part)
The upper part contains all the technical components for the pressure boost such as the
pump and pressure switch. This part can be exchanged for maintenance or if there is a dis-
ruption of service. The operator cannot and may not service or repair anything in or on this
upper part. The upper part is serviced and repaired on the manufacturer's premises.
The upper part is correctly placed on the lower part (see section 8.4) and then it's just nec-
essary for the plug for the voltage supply (120VAC) to be plugged into the network socket.
The DE is operational as soon as its network switch (1) has been turned on. The pump,
which is in the upper part, goes on when a sufficient quantity of water is present in the in-
terim tank. The water level is monitored by two float valves (2). The pump forces the water
from the interim store into a standing storage tank. The pump stops when a system pres-
sure of 5 bar (73 psi) has been reached. The system pressure can always be read on the
manometer (3). When the standing and interim tanks are full, the DE is in stand-by mode.
The system pressure goes down as water from the standing tank is used. When this pres-
sure reaches 3 bar (44 psi) the DE starts boosting it again until it has risen to 5 bar (73 psi).
The switch on and switch off points are regulated by a pressure switch. In addition, the DE
is equipped with a safety pressure switch (4). This switch is triggered at 6 bar (87 psi) and
can only be reset mechanically (see section 7.1 for further details).