


Float valve - Bottom of water tank
Presentation
The float valve aims at keeping on a determined level the stretch of water in a water tank. It is set up on the supply pipe at the bottom.
It opens when the water tank goes down below the chosen level and closes progressively whenever the maximal level is reached.
Its essential properties are:
- its lightness,
- its dismantling easiness thanks to its simple construction,
- its maintenance easiness thanks to its low components number,
- functioning without vibrations nor water hammers.
There are float valves from DN60 to DN300 for a service pressure of 10 bars.
The float valve can be set up at the bottom of a water tank in immersed position.
Material and coating
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Item | Designation | Material | Coating |
1 | Body and cap | Steel type AE 250 | Epoxy powder thickness mini 200 microns |
2 | Piston and lining | PVC | |
3 | Check valve – holder axis | Steel type Z6 CN 18.09 | |
4 | Check valve | Steel type Xc 38 | Epoxy powder thickness mini 200 microns |
5 | Check valve joint | SRB supply | |
6 | Lever | Steel type Xc 38 | Epoxy powder thickness mini 200 microns |
7 | Roller | Steel type Xc 38 | Epoxy powder thickness mini 200 microns |
8 | Piston joint | Nitrile | |
9 | Immersed body | Expanded Polystyrene CL5 | |
10 | Chain | Inox type A 304 |
Installation plan
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DN | D | E |
mm | mm | mm |
60 | 350 | 140 |
80 | 400 | 160 |
100 | 450 | 160 |
125 | 600 | 175 |
150 | 650 | 180 |
200 | 750 | 215 |
250 | 850 | 250 |
300 | 950 | 290 |
Length of the delivered chain: 5 meters to adjust when setting up.
Hydraulic characteristics
Headloss expression by Kα
The headloss ΔH of a valve, the flowing speed of a fluid and the headloss coefficient K in the valve are tied by the following formula:
∆H = Kα × V² 2g
with ΔH = headloss in mCE, V = fluid speed in m/s, g = gravitational acceleration in m/s², Kα = headloss coefficient without dimension
Span | 25% | 50% | 75% | 100% |
Kα | 98 | 32 | 16 | 12 |
Marking
There’s a unique marking on the valve’s body (description).
This description mentions:
- nominal diameter for entrance,
- service pressure,
- drilling template for flanges,
- serial number,
- manufacturing date.