OPERATING MANUAL
07-2021
8/11
Horizontal piping –
vertical orientation
Horizontal piping – horizontal
orientation
Vertical piping
Fig. 2. Orientation of the valve closure pivot shaft relative to the piping plane shown for P/N 4497 DN100
Fig. 3. Recommended installation method
shown for flange-to-flange valves
The optimum installation orientation of concentric butterfly valves is to have the closure panel axis vertical with
the closing movement of the closure panel bottom opposite to the medium flow (Fig. 3). While the valve is being
closed or opened, the medium is at its maximum flow rate and entrains the contamination settled in the
neighbouring part of the pipeline. The valve installation shown in Fig. 3 considerably extends the service life and
operating reliability even with media loaded with contaminants which by their weight tend to settle down in the
piping. A consequence of this is that the deposits can be entrained from the upstream of the valve by the maximum
possible flow passing the bottom part of the valve closure during the opening operation (Fig. 4).
Fig. 4.
A – Incorrect valve closure pivot
shaft orientation
B – Incorrect valve closure pivot
shaft orientation
C – Correct valve closure pivot shaft
orientation
When designing the installation, consider that the horizontal orientation of the valve closure pivot shafts is the best
for operating performance and reliability:
1.
the weight of the pivot shafts and the closure rests on both bearings;
2.
the front-end bearing of the pivot shaft is unloaded;
3.
the valve operating life is extended, especially when the liquid medium contains solids which tend to
settle at the bottom of the piping.
If the valve is installed with the valve closure pivot shafts aligned vertically, the solids are not effectively entrained
by a super-nominal flow; this may result in damage to the valve closure edges or the sealing ring mating edges.
Any change in the operating conditions must be consulted with the manufacturer beforehand.
