WILO SE 02/2014
4
English
6. Description and operation
6.1 General description
The pressure-maintaining system is a compact
installation which is supplied completely piped-
up and ready to connect.
Only the connections for suction and discharge
as well as to the power supply must be provided.
Every accessory ordered is delivery separately.
The relevant instructions or standards must be
observed for the connection to the public water
supply mains. Regulations from the water com-
panies must be included where appropriate. Local
conditions (e.g. a supply pressure that is too
high or fluctuates considerably and which might
require the installation of a pressure relief valve)
must also be observed.
6.2 Description of the product
6.2.1 Mechanic and hydraulic installation compon-
ents (Fig. 2a, 2b, 2c and 2d)
•
The compact installation is mounted on a steel
base frame. It consists of a group of 1 to 2
high-pressure centrifugal pumps (pos. 1) with
filling stopper (Fig. 1a) and emptying one (Fig.
1b) and also a switchgear (pos. 2).
For the vertical versions (Fig. 2d)
•
A supply manifold pipe (pos. 3) and a delivery
manifold pipe (pos. 4) in stainless steel 304.
•
A shut-off valve (pos. 5) is mounted on the suc-
tion and delivery side of each pump (pos. 6).
•
A non-return valve (pos. 7) on the delivery side
of the pump.
•
1 or 2 discharge valves (pos. 8) depending on the
version, with one sieve filter (pos. 9), 2 isolation
valves (pos. 10a and 10b) and 1 control button
(pos. 11).
•
A unit composed of a pressure sensor (Fig. 3b,
pos. 15), manometer (Fig. 3b, pos. 14) and a
shut-off valve (Fig. 3b, pos. 16) is mounted on
the discharge manifold.
ATTENTION!
When pumps are running, the shut-
off valve (pos. 16) must be open.
For the horizontal versions (Fig. 2a, 2b, 2d)
•
A discharge manifold (pos. 4) in stainless steel
304 for versions with 2 pumps.
•
On each pump, an isolation valve (pos. 5) is
mounted on the suction side and pressure side
(pos. 6) (2-pump version).
•
A non-return valve (pos. 7) is mounted on the
discharge side.
•
1 or 2 discharge valves (pos. 8) depending on the
version, with a sieve (pos. 9).
•
An isolation valve of the pump for 1-pump versi-
on (pos. 12).
•
A unit composed of a pressure sensor (Fig. 3b,
pos. 15), manometer (Fig. 3b, pos. 14) and a
shut-off valve (Fig. 3b, pos. 16) is mounted on
the discharge manifold.
ATTENTION!
When pumps are running, the shut-
off valve (pos. 16) must be open.
Moreover, all systems are delivered with:
•
Float for filling control (pos. 17) to be mounted
on the tank.
•
Float switch against a low water level, for dry run
protection (pos. 18) to be mounted on the tank.
•
A unit with a filling electrovalve (Fig. 4, pos. 19)
and a stop valve (Fig. 4, pos. 20) to be mounted
on the tank.
The switchgear (pos. 2) is mounted on the base
frame by means of a stand (pos. 21). All electric
components are delivered in a ready-wired state.
6.2.2 High-pressure centrifugal pumps (pos. 1)
Different types of multistage high-pressure cent-
rifugal pumps are installed in the pressure-main-
taining system depending on the intended use
and the performance parameters required. The
attached installation and operating instructions
provide further information about the pumps.
6.2.3 Switchgear (pos. 2)
Different switchgears and control devices of dif-
ferent constructions (with or without speed con-
verter) can be integrated and delivered to activate
and control the pressure-maintaining system. The
attached installation and operating instructions
provide further information about the switchgear.
6.3 Function of the pressure-maintaining system
The pressure-maintaining system is equipped
with non self-priming, multistage high-pressure
centrifugal pumps as standard.
Under the pressure of the heating or cooling loop
a certain pressure is maintained.
When this pressure becomes too strong, the dis-
charge valves open to let water coming into the
tank and reduce the system pressure.
When this pressure becomes too low, a pump
starts to recharge the water and the water pres-
sure is increased by the system.
The pressure monitoring is achieved through the
pressure sensor. The actual value of the pressure
is continuously measured and transmitted to the
control panel. As appropriate, the control unit
starts, commutes or stops the pumps until the
preset control parameters are met.
The system also provides a filling of the tank if
necessary through the float and fill valve. (The
instructions for installation and commissioning of
the switchgear contains a more detailed descrip-
tion of the type and method of regulation).
Associated with the tank, the pumps are also used
for initial filling of the installation.
7. Installation and hydraulic connection
7.1 Installation
Install the pressure-boosting system in a room
which is easy to access, well ventilated, frost-
proof and protected against rain.
Be sure that the dimension of the technical room
door is adequate to enter a pressure-maintaining
system.
Adequate space must be provided for main-
Summary of Contents for WEH
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