ARI Armaturen FABA-LA EN - Manual (Page 8)

Page 8 Rev. 0040103002 0410
Operating and installation instructions
FABA
®
-Plus / FABA
®
-Supra / FABA
®
-LA
5.3 Installing valves with pressure balancing plugs
Valves with pressure balancing plugs have to be installed with medium flowing over the
plug (pos. 3) as indicated by flow direction arrow on valve body.
Working principles:
When the valve is closed, anticlockwise rotation of the hand wheel lifts the pilot plug (pos.
3.1) off the larger balancing plug (pos. 3). This allows the medium to pass through the plug
and equalizes the pressure of the medium under the plug (pos. 3). After the pressures have
been equalized within the values stated in the table below, the valve can be opened by
turning the valve further.
- Pressure balancing plugs are fully effective only in closed line section.
- The pressures of the medium on either side of the plug cannot be equalized if the medium
is discharged into “open air”.
- If adequate pressure equalisation cannot be achieved using a pressure balancing plug,
other design solutions must be used instead (e.g. a bypass line).
5.4 Installation data on valves with loose plugs
The data given in point 5.3 applies to the maximum differential pressure. The set pressure
is 0,1 bar. The valve should only be installed in horizontal lines in an upright position.
5.5 Installing valves with limit switches
The valves with limit switches must be connected up as shown in the plans of the plant on
the basis of their working principles.
ATTENTION !
The stop valves must be equipped with pressure balancing plugs if the
differential pressures listed in the table below are exceeded in the closed state.
Valves with pressure balancing plugs should be installed so, that the pressure of
the medium acts on the plug (pos. 3) and the stem is vertically upright.
Fig. 9
Balancing plug DN 125 150 200 250 300 350 400 500
Pressure difference ΔP 25 bar 21 bar 14 bar 9 bar 6 bar 4,5 bar 3,5 bar 1,5 bar
ATTENTION !
Note direction of flow.