Air Control - Steffens WL Bedienungsanweisung

1
3 4
Fig. 7 Fitting of throttling disc
Pos. Description
1 Throttling disc
Throttling disc, approx. 2 mm thick, made of copper or
2
brass
3 Suction flange
4 Gaskets
6 Suction socket
Throttling disc bore diameter table
At 0 - 2 m
Flow rate l/h
suction lift
d in mm
1000 9
1500 10
2000 12
2500 13
3000 15
4000 17
5000 19
If the inlet pressure fluctuates by more than 0.5 bar, it is not
sufficient to throttle by means of the throttling disc. In this case,
an open intermediate tank should be installed.
5.4.2 Discharge pipe
The discharge pipe should be as short as possible. No elbows
should be used, only pipe bends, if required. It is not
recommended to install a non-return valve as this will cause
unnecessary resistance and hammering. The pump valves are
designed as non-return valves, so that the water does not flow
backwards - unless of course the rubber discs of the valve are
defective. On systems with vertical pressure tank, it is
recommended to fit an isolating valve in order to avoid having to
drain the pressure tank when the pump or the suction or
discharge pipes are to be repaired.

5.5 Air control

5.5.1 Snifter valve and air controller
The snifter valve ensures air supply to the pump air chamber and
the pressure tank. There are two versions:
Standard valve
for manual air supply
Fig. 8 Standard and special valve
8
2
Ø according to table
5
At 0 - 3 m At 3 - 10 m
inlet pressure inlet pressure
d in mm d in mm
7.5 5
9 6
10 7
12 8
13 10
14 12
16 14
Special valve
for automatic air supply
We urgently recommend to operate pump
systems with an air controller. This is the only
method to ensure that the consumed air cushion
of the pump air chamber and the pressure tank is
Caution
replenished. In case of insufficient air supply to
the pump air chamber, the automatic pressure
relief unit (safety valve) will be activated.
Replenishing of air in pump systems with standard snifter
valve
In order to replenish the air cushion, the lock nut of the snifter
valve should be loosened and the adjusting screw slackened
approximately two turns. The correct water and air cushion levels
are illustrated in the figure below:
Correct level of the
air cushion.
Water level when
switching-off.
= 1/2 vessel height
Fig. 9 Correct water and air cushion levels
Replenishing of air in pump systems with special snifter
valve and air controller
The air controller automatically adjusts the air cushion of the
pressure tank to the optimum level. Depending on the water level,
the float is lifted by rising water level, thus opening a valve in the
air controller, meaning that the pump draws in air via the suction
inlet of the air controller and passes it on to the tank. If there is
sufficient air in the pressure tank, the water level stops rising. The
float is not lifted any further and the air suction inlet remains
closed.
2
1
6
Fig. 10 Replenishing of air
Pos. Description
1 Hose for special pump snifter valve
2 O-ring
3 Tank sleeve
4 Lever
5 air controller
6 Suction inlet
When air-
cushion too
small, high
switching
frequency
3
4
Version horizontal
tank (FILIA,
FILIUS units)
5