A float rises inside a tapered borosilicate tube until the forces balance. The position of the float gives the flow rate directly on the scale—simple, visible and independent of a power supply.
A float rises inside a tapered borosilicate tube until the forces balance. The position of the float gives the flow rate directly on the scale—simple, visible and independent of a power supply.
The pressure drop across the float is equal to its weight divided by its maximum cross-sectional area in the horizontal plane. Both in orifice type meter and in the Rotameter, the pressure drop arises from the conversion of pressure energy to kinetic energy and from the frictional losses.
A rotameter may therefore be considered an orifice meter with a variable aperture, and the formula derived for the orifice meter applies here with only minor changes.
The borosilicate tube can be replaced without taking the meter out of the pipeline.
A detachable scale is printed with flow in the customer's engineering units, 175 to 200 mm long.
End connections rotate through 360°, with top and bottom, rear, bottom and rear, or rear and top orientation.
Sturdy metallic construction withstands line stress and vibration, with an adjustable packing gland.
Standard product family; other materials on request
| Accuracy | +/- 2% of full scale |
|---|---|
| Rangeability | 10 : 1 |
| Repeatability | 0.5% |
| Overall length | 500 mm in flanged versions |
| Scale length | 175 - 200 mm |
| Line size and flow | 1/2″ to 4″ line size and max flow upto 30,000 LPH |
| End connections | Can be rotated through 360° |
| Connection orientation | Top & bottom, rear, bottom and rear, rear and top |
| Floats | Standard interchangeable floats for a given size |
| Tube | Borosilicate glass tube |
| Float MOC | SS 304 / SS 316 / Teflon, other material on request |
| End fittings | CS, MS, SS 304, SS 316, rubber lined, PTFE lined |
| Process connection | Threaded or flanged (ASA 150 #, BS 10 Table D/E or as per customer's requirement) |
| Packing | Neoprene / Teflon / Silicon / Viton |
| Frame | MS / CS powder coated as standard, SS optional |
| Cover | MS / aluminium cover with safety glass or acrylic window |
| Bolts | CS / SS 304 / SS 316 |
| Gland housing | Cast steel, epoxy painted |
| Options | Adjustable packing gland; high and low alarms; wide choice of flow ranges for individual requirement |
Flow range depends on line size, float material and fluid; the figures above describe the standard family. Confirm the calibrated range for your fluid at enquiry stage.
The tube, float and scale are common to every build. What changes is the frame, the end fittings and where the connections point, so the meter suits the run it has to sit in.
The standard build. MS or CS frame, powder coated, with flanged end fittings and a safety-glass window over the tube.
Stainless frame and cover for wash-down areas, corrosive atmospheres and plant where painted steel is not accepted.
A shorter body for small line sizes and low ranges, with the tube carried in a stainless armour frame between flanged fittings.
Connections taken out of the back of the meter so the body sits flush against a panel and only the scale faces the operator.
Send the fluid, flow range, line size, pressure, temperature and connection. We will confirm the tube, float, scale and calibrated range.