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Tri Gear Flow Meter

Tri Gear Flow meter

Tri-gear Flow meters are precise, reliable and rugged instruments for the volumetric flow of liquids in general industrial, petroleum and chemical applications that require high degrees of accuracy and repeatability. They operate on the Positive Displacement principle using advanced gear technology and offer a competitive alternative to their Oval Gear, Sliding Vane and Bi-Rotor alternatives.

tri-gear-large-flow-meter
tri-gear-large-flow-meter

Operation Principle

Liquid Passes into the single case measuring chamber and displaces two Trigears. Each rotation of a Tri-gear is proportional to a discrete unit of volume, in turn, the speed at which the gears rotate is directly proportional to flowrate. Reed and Hall Effect sensors mounted outside the pressure boundary detect the movement of the Tri-gears, thus allowing local or remote instruments to display flow total, rate of flow or facilitate batching applications.

Meters can be fitted with additional sensors to provide in phase or out of phase signals for applications such as bidirectional flow.

Benefits

  • High Resolution Digital Output
  • Wide Rangeability
  • Bi-directional flow capability
  • Digital or Analogue Outputs available.
  • HART Output option
  • Less slippage than oval gear meters.
  • Smoother and quieter than Oval Gear Meters.
  • Dual Output standard (reed and hall effect)
  • Low Mass Tri-gears facilitate fast response time to step changes in flowrate.

Technical Specifications

Maximum flow is to be reduced as viscosity increases, see flow de-rating guide.
Max. allowable pressure drop is 140Kpa (20psi).
Model Prefix TG008 TG015 TG020 TG025 TG040 TG050
Capacity Group Small Capacity Medium Capacity
Nominal size (inches) 8mm (3/8”) 15mm (1/2”) 20mm (3/4”) 25mm (1”) 40mm (1.5”) 50mm (2”)
*Flow range – litres/min
– US gal/min
0.25 ~ 9.2 1-40 2 ~ 50 5 ~ 150 10 ~ 250 20 ~ 500
0.07 ~ 2.4 0.3 ~ 10.5 0.6 ~ 13 1.3 ~ 40 2.6 ~ 66 5 ~ 132
**Accuracy @ 3cp ± 0.5% of reading ± 0.25% of reading (15:1 turndown),
± 0.5% of reading (25:1 turndown)
Repeatability typically ± 0.01% of reading
Temperature range -20°C ~ +120°C (-4°F ~ +250°F), refer factory for lower & higher temperatures
Maximum pressure (threaded meters) bar (PSI)
Aluminium Meters 30 (440)
316 Stainless Steel meters 34 (495) 30 (440)
High Pressure models refer factory
Electrical – for pulse meters (see below for optional outputs)
Output pulse resolution Pulses/litre (pulses/US gallon) – nominal
Reed Switch and Hall Effect 670
(2546)
77
(292.6)
77
(292.6)
33.5
(125.4)
11.5
(43.7)
6.5
(24.7)
High Resolution Hall / Quadrature 1340
(5092)
154
(585.2)
154
(585.2)
67
(254.6)
23
(87.4)
13
(49.4)
Reed Switch output 30Vdc x 200mA max. (maximum thermal shock 10°C (50°F)/minute)
Hall Effect output (NPN) 3 wire open collector, 5 ~ 24Vdc max., 20mA max.
Optional outputs 4 ~ 20mA, scaled pulse, quadrature pulse, flow alarms or two stage batch control
Physical
Protection class IP66/67 (NEMA4X), integral ancillaries can be supplied Intrinsically Safe
Noise generation @ maximum flow - 75db
Dimensions Refer datasheet
Pressure drop chart Refer datasheet
Min. filtration – microns (mesh) 75 microns
(200 mesh)
150 microns (100 mesh)
Approximate shipping weights (basic threaded meter) kg
Stainless Steel 2.2 3.0 3.0 4.0 9.0 12.0
Aluminium 1.0 1.5 1.5 2.0 4.0 6.0