Wolman type water meters can be used for flow rates higher than Qn 15 m3/h. They are thereby distinguished by ensuring an especially low head loss, even with high flow rates.
The newly develoved measuring insert with a special construction of the turbine where the water flows through, guarantees a hign measuring accuracy and long-term stability of the measuring results. Largen number roller on the dry dial counter ensure the readability of the number at all times.
Similar to multi-jet meter, Wolman meters measure the velocity of the water flowing through eith the help of a turbine. The volume is mechanically calculated, through the known volume of the measuring chamber, and indicated with the roller counters in cubic meters. The unique form of the “paddle wheels” enable the wolman meters to cover a very large measuring range with especially low head loss. Aside from their construction for high flow rates, they also reliably start measuring with small water quantities.
Active or passive sensors are available for communication with pulse counting modules or automation and control systems. Inductive NAMUR optical and reed sensors can be retrofitted without damaging the calibration seal. Active sensors have a pulse value, depending on the meter size, of either 1 or 10 L/lmp. Reed sensors have a pulse value of 100 L/lmp up to m3/lmp, depending on the meter size.
Wolman Meter With Parallel Turbine Shaft
Wolman parallel type meters are always used whwn high flow rates with a relative constant flow rate profile are to be measured. Through its robust construction they not only are capable of covering a large measuring range, but the measuring accuracy is also long-term stable.
The hydrodynamic optimize turbine is reliably operated already at small flow rates and :upwards” it has enough power reserves to reliably measure flow rate peaks. Especially strong bearings with low friition guarantee a long life of the meter.
Reed sensors, optical and inductive – namur sensors always be retrofitted without damaging the-calibration seal. Then the meter can be integrated with data communication or automation and control system in a simple and flexible way.
Performance characteristics in overview
- Low starting, high overload security
- Wide measuring range
- Removable measuring insert
- Low head loss
- Hydraulic bearing relieve for long term measuring stability
- Retrofittable with active and passive pulsers
- Metal protective cover serially, plastic optional
- Evacuated counter protected from condersation
- Dry dial counter with large number rollers simplifies the readability
- For cold water up to 30°C, with securitu up to 50°C
- For horizontal, vertical and inclined installation position
- High pressure model PN25/40 upon request.
Technical Data :
| Nominal Flow Qn | 40 m3/h |
| Nominal Diameter (DN) | 80 mm |
| Overal Length (L) | 225 mm |
| Metrological class | B |
| Maximum Flow (Short-term)Qmax | 150 m3/h |
| Maximum Flow (Constant) | 90 m3/h |
| Minimum Flow Qmin | 0.8 m3/h |
| Flow rate with 0.1 bar head loss | 70 m3/h |
| Display range | min 2 max (9.999.999 m3) |
| Maximum temperature | 50°C |
| Operating pressure, max (PN) | 16 bar |
| Head loss at Qmax | 0.2 bar |
| Flange diameter (D) | 200 mm |
| Height | 255 mm |