The tekVar series is a comprehensive range of variable area flow sensors, which indicate the flow rate of gases and low viscosity liquids. Although simple in construction and low in cost, all sensors are provided with a USA NIST traceable Calibration Certificate, and are manufactured with ISO 9001 quality guarantee.
tekVar metal tube VA sensors are suitable for gases and low viscosity liquids for 15 – 100mm (0.5″ – 4″) pipes. A sensing float in an internal tapered metal flow tube is magnetically coupled to the indicator unit, which provides flow rate analog or digital scaling over a 10 : 1 range. A 4 – 20mA output is available. A wide range of process flanges provide pressure ranges from 20 – 92 barg (290 – 1330psig)
Accuracy depends on tekVar type, but varies from ± 2 % of full scale to ± 5 % of full scale. Liquid flow rates range from 2.5 to 100000 lpm (0.01 – 440 gpm), or gases from 0.07 – 2500 nm3/hr (2.5 – 89000 scfh) normally over a 10 : 1 range.
Features
tekVAR Metal tube VA
- Accuracy : < ±2.0% of full scale USA NIST and international traceability
- Connections : DN15mm – 100mm (1/2″ – 4″), JIS10K or ANSI 150lb
- Flow Tube/Float: Mat’l of SS304, 316, 1.4571ti, Hastelloy C
- Flow Ranges :
mm inches Water (lph) Water (gpm) Air(Nm3/hr / scfh) 15 0.5" 2.5 - 630 0.01 - 2.8 0.07 - 16 / 2.5 - 570 25 1" 63 - 4000 0.28 - 18 1.6 - 110 / 60 - 3900 50 2" 630 - 16000 2.8 - 70 18 - 400 / 640 - 14500 80 3" 2500 - 40000 11 - 180 70 - 1000 / 2500 - 36000 100 4" 6300 - 100000 28 - 440 60 - 2500 / 5700 - 89000
Notes : For each size flow ranges are in 10 :1 increments - Pressure : 0.6MPa – 1.6MPa
- Temperature : minus 25°C to + 150°C (-13°F to +300°F)
- Indicator : mechanical analog or LCD/analog
- Transmitter : analog 4 -20mA
- Protection : IP65 weatherproof and NEMA 4X
- Options : Temperature sheild for high temperature application
tekVAR Glass tube VA
- Media : Gas and low viscosity liquids
- Accuracy : < ±2.5% of full scale USA NIST and international traceability
- Flow Tube / Seal: Tough Borosilicate Glass / Viton, EPDM
- Float : PTFE (gases), AISI 316 stainless steel (liquids)
- Connections : 1/2″ – 2″ FNPT or FBSPT or flange to DIN PN10, JIS10K, ANSI 150lb in AISI 304 or 316 SS
- Pressure : < 1.0MPa
- Temperature : minus 25°C to + 150°C (-13°F to +300°F)
- Protective Cover : Epoxy coated carbon steel or stainless steel 304
The tekVar series is a comprehensive range of variable area flow sensors, which indicate the flow rate of gases and low viscosity liquids. Although simple in construction and low in cost, all tekVar sensors are provided with a Calibration Certificate traceable to both USA NIST and UK Accreditation Service (UKAS). They are also manufactured in quality strictly in accordance their ISO 9001 approval.
The tekVar embodies a vertical tapered transparent flow tube of tough borosilicate glass or various transparent plastics. These are scaled on the outside in various flow rates units for liquids or gases. Inside the flow tube is a hydraulically designed “float”, which is not an accurate description since it has a density always larger than the media being measured. At no flow condition the float rests at the bottom of the flow tube. Upward flow of media causes the float to rise to a position which maintains the pressure drop across it in equilibrium with the effects of gravity and bouyancy forces acting upon it. Since the immersed weight of the float is constant within the media being measured, the pressure drop across it must also remain constant. Therefore, as the flow rate increases, the float will rise in the tapered flow tube to provide a larger annular area, through which the media passes. Hence the float takes up a height position, which is an indication of the flow rate, calibrated with NIST and UKAS traceability.
For optimum accuracy it is imperative that the float remains concentric with the tapered flow tube, even with no straight pipe runs at either end of the tekVar. This is accomplished with tekVar sensors, by both precision engineering and various hydraulic designs of the float, in which aerodynamic flutes are embodied to provide a stabilising, concentric rotation. For large flow sensor floats, a friction-free guide rod is incorporated.
tekVAR Flow Cell Orifice By-Pass
- Accuracy : < ±2.5% of full scale
- Connections : DN10mm – 500mm (3/8″ – 20″), JIS10K or ANSI 150lb
- Flow Ranges :
mm inches H2O (m3/hr) H2O (gpm) Air(Nm3/hr) 10 0.5" 0.08 - 0.42 0.35 - 1.85 0.8 - 4.0 100 4" 16 - 80 70 - 350 160 - 800 250 10" 90 - 480 400 - 2200 900 - 5000 400 16" 300 - 1500 1300 - 6600 3000 - 14500 500 20" 500 - 2500 2200 - 11000 5000 - 24000 - Accuracy : < ± 5% of full scale
- Connections : 1/8″ NPT – 1/4″ NPT or BSP
- Working press : max 6 barg (87 psig)
- Flow Ranges :
inches H2O (mlpm) H2O (m3/hr) Air (mlpm) Air (scfh) Weight (kg) 1/8" 20 - 200 0.3 - 3.0 0.3 - 3.0 0.7 - 7.0 0.5 1/4" 50 - 500 0.8 - 8.0 1.0 - 10 2.5 - 25 0.5 1/4" 0.1 - 1 lpm 1.6 - 16 2.0 - 20 4.5 - 45 0.5 1/4" 0.2 - 2.0 lpm 3.0 - 30 5.0 - 50 11- 110 0.5 - Accuracy : < ± 5% of full scale
- Connections : 1/2″ – 2 1/2″ NPT or BSP or BSPT or PVC glue ends
- Flow tube / Float : Acrylonitrile styrene or polycarbonate / PVDF or SS
- Flow Ranges :
mm inches H2O (lpm) H2O (gpm) Max temp / pressure 20 3/4 4.0 - 40 1.0 - 10.0 60°C (140°F) / 6 barg (87 psig) 25 1 8.0 - 80 2.0 - 20.0 ditto 50 2 20 - 180 5.0 - 45.0 ditto 63 2 1/2 200 - 1000 50 - 250 ditto
