Description
The QWKA is a vortex flowmeter based on the Kármán vortex street, with no moving part in the meter tube. It is particularly suited to saturated steam, superheated steam, gases and viscous liquids at medium temperatures up to +250 °C, in the high-temperature version up to +350 °C.
Vortices shed behind a bluff body, their frequency is proportional to the flow velocity. Flow ranges per nominal size and medium per range table, giving a turndown of about 11:1 to 23:1. Accuracy ± 1.0 % for all three media, repeatability 0.3 % (R), the reference is not explained. Output three-wire voltage pulse (code F) or two-wire 4 … 20 mA with display (code A). Supply +24 V DC. Connection flange or wafer (clamp) type, nominal sizes DN25 … DN300.
Body of stainless steel. Nominal pressure 1.6, 2.5 and 4.0 MPa per parameter block. Medium temperature -40 … +250 °C, high-temperature version +100 … +350 °C (code H). Counter flanges are not supplied, no flange standard is named. The protection grade is not documented. An explosion-proof version is a digit of the order code; gas group, temperature class and certificate are not named. A declaration of conformity is not documented in the datasheet. Before sizing, note: the size range is given three different ways (DN25 … DN300, DN15 … DN300, range table without DN32). The order code offers 2.5 and 4.0 MPa only, not 1.6 MPa. For steam the range table applies to dry saturated steam only.
Advantages at a glance
- Kármán vortex street, no moving parts
- For saturated steam, superheated steam, gas and liquid
- Accuracy ± 1.0 %, repeatability 0.3 %
- Medium temperature up to +250 °C, high-temperature version up to +350 °C
- Flange or wafer type
- Nominal sizes DN25 … DN300
- Two-wire 4 … 20 mA with display or pulse output
- Temperature and pressure compensation optional