The BMV flow rate indicator is a variable area flow rate indicator. The instrument must be mounted on a vertical pipe with ascending flow. The acceptable fluid viscosity is close to water viscosity. These instruments may be available for airflow rate indication and control: on request.
The built in magnet of the diver drives the indicator. Coupling of both devices allow a continuous indication even with quick changes in the flow rate. The Reed contact, by side, is continuously adjustable. The switch is bi-stable and NO (normally open with flow less). It acts when the diver passes in front of it.

Maximal pressure Brass: 200 bar
Stainless steel: 300 bar
Temperature: 0...100°C (160°C on request)
Scale: In L/min of water at 20°C

Accuracy:
5 %
Bi-stable switch NO (flow less), 250 V / 1.5 A / 50 VA

Protection: IP 65
Connector: 43650 – cable inlet: PG 9
Brass model wetted parts: brass and NBR seals
Stainless steel model wetted parts: SS316 and FPM seals

Options (on request)

Switch:
Change over contact
ATEX certified switch for Ex area

Seals: FPM, NBR, EPDM

Caution:
Verify the right correspondence of the switching power of the switch and your process device. A protective relay is described on data sheet 250-02.

SWITCHES: Features

The switch fits on the dovetail (rear face) and is continuously adjustable; the position is secured with a blocking screw.
The plastic DIN plug (DIN 43650) is IP65, with a cable inlet PG9.

Standard contact, NO (flow less)
Max. 230 V / 1 A / 50 VA

Change over contact (Option)
Max. 250 V / 1.5 A / 50 VA

ATEX certified contact
EEx m T6 - NO max. 250 V / 2 A / 60 VA – Change over contact max. 250 V / 1 A / 30 VA
Atex II 2G EEx m II T6 - NO max. 250 V / 2 A / 60 VA – Change over contact max. 45 V / 1 A

- The flow monitor must be installed vertically in the flow circuit.
- Flow direction is from bottom to top.
- Flow media must be free of particle contamination, otherwise the instruments will not function properly. We recommend the use of dirt filters type SF or SFD.
- The flow monitors must not be positioned in inductive fields. Minimum distance from iron parts : 10 mm.
- Switch point adjustment :
The arrow marking the switch-off point is positioned in line with the required flow rate, marked on the scale attached to the body.

- The flow indicators BMV are designed for a vertical mounting with an ascending flow.
- The fluid should be free of solid particles (a filter could be used before the BMV).
- All area must be free of magnetic fields.
- The fittings and or adaptors must be non-magnetic (made of brass, stainless steel or plastic).
- Any magnetic device should be at least above 10 cm from the BMV.

Gravity and magnetism ensure absolute operational reliability. There are no wearing parts such as springs, hinges or membranes.

The switch ranges given below refer to the limits within which the switch point may be infinitely adjusted. The actual flow throughput can, depending on the flow velocity, be much greater.

Hysteresis is the difference in flow between the switch closing and opening again. The difference is the result of the movement required by the float to reclose the open contact. The shorter the distance, the smaller the hysteresis and therefore the more accurate the instrument.
By means of the careful choice of magnets and reed switches with especially close tolerances, hysteresis is kept to an absolute minimum.
Low hysteresis is of great advantage where particular accuracy is demanded, especially in flow systems where only small increases in flow throughput above the necessary minimum can be achieved.

Monitoring of cooling circuits in welding machines, induction heating plants, high frequency generators, condensers, transformers, compressors, flow heaters, steam generators, centrifuges.
Monitoring of sealing media for seals and pump dry running, motor cooling systems, mixing plant, hydraulic systems etc .
We reserve the right to carry out technical amendments.