ARI Armaturen STOBU PN 40 EN - Manual (Page 7)

Operating and installation instructions
STOBU
®
PN16-40
Rev. 0040102000 1113 Page 2-7
5.3 Installing valves with balancing plugs
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).
ATTENTION !
ARI 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. 5
Balancing plug DN 125 150 200 250 300 350 400 500
Pressure difference P 25 bar 21 bar 14 bar 9 bar 6 bar 4,5 bar 3,5 bar 1,5 bar
ATTENTION !
Note direction of flow.