RHM 15

FLOW SENSOR

The RHM 15 is an all-purpose meter suitable for liquid processing plants. A wide application flow range capability allows for commonality of installation across numerous lines – a real benefit to owners and operators.

  • Range: 0 kg/min up to 240 kg/min
  • Pressure: up to 477 bar (6918 psi)
  • Temperature: -196°C (-321°F) up to +350°C (662°F)
  • Accuracy: 0.1 % of rate
  • Materials: SS 316L / SS 316Ti, Alloy C22 – 2.4602, Super Duplex – 1.4410, Tantalum – UNS R05200
  • Process Connection: ¾" up to 2"
CONFIGURE
CATEGORY Medium Size Sensors, Chemical Injection, Fuel Consumption, Oil Measurement, Painting/Coating Lines, Plastics Production

Performance Data

 

Flow Measurement Uncertainty
Selected Sensors down to ±0.10 % ¹ of rate (Gold Line)
Standard Sensors down to ±0.15 % ² of rate

Flow Measurement Repeatability
Down to ±0.05 % of rate

Temperature Measurement
Better than ±1 °C

Density Calibration (Liquid)
Selected Sensors down to ±0.0005 kg/liter (Gold Line)
Standard Sensors down to ±0.0025 kg/liter 

Measurement Tube Pressure Ratings

The maximum pressure (pmax) of a sensor is determined by its lowest rated part. The lowest rated part can be either the measurement tube (pmax indicated below), the connection block/manifold
(pmax indicated in the mechanical construction section) or the process connection (for pmax see published standards or manufacturer information).

 

 

50 °C
122 °F

120 °C
248 °F

210 °C
410 °F

350 °C
662 °F

SS 316Ti (standard)
Low pressure

165 bar
2393 psi

150 bar
2176 psi

127 bar
1842 psi 

107 bar
1552 psi

Alloy C22

228 bar
3307 psi

201 bar
2915 psi

172 bar
2495 psi 

143 bar
2074 psi

Tantalum

86 bar
1247 psi

66 bar
957 psi

53 bar
169 psi

n/a

SuperDuplex
Low pressure ³

395 bar
5729 psi

346 bar
5018 psi

313 bar
4540 psi

n/a

SS 316Ti (standard)
Medium pressure

352 bar
5105 psi

300 bar
4351 psi

250 bar
3626 psi

210 bar
3046 psi

Alloy C22

540 bar
7832 psi

477 bar
6918 psi

407 bar
5903 psi

339 bar
4917 psi

Super Duplex
Medium pressure ³

882 bar
12792 psi

773 bar
11211 psi

699 bar
10138 psi

n/a

SS 316Ti (standard)
High pressure

540 bar
7832 psi

450 bar
6527 psi

350 bar
5076 psi

300 bar
4351 psi

 

Uncertainties and flow measurement turn-down

All uncertainty statements refer to reference conditions – mass flow of water, 18 – 24 °C, 1 – 3 bar in a standard temperature, pressure and material configuration sensor. The sensor can be used to measure gas – uncertainty values for gas equal the liquid value plus 0.3 %. Reference conditions for gas are mass flow of natural gas, 18 – 24 °C, 35 to 100 bar in a standard temperature, pressure and material configuration sensor.

The turn down capability from Qnom of the flow sensor is driven mainly by its zero point stability. At the very low end of the measuring range the uncertainty (u) is dominated by zero point stability. The zero point stability of a standard sensor is: 0.02 kg/min (0.0441 lbs/min). Zero point stability of a Gold Line sensor is 0.012 kg/min (0.0265 lbs/min).

For flow Q ≥ zero stability / (calibration uncertainty/100) u = calibration uncertainty
For flow Q < zero stability / (calibration uncertainty/100) u = (zero stability/Q) x 100

Uncertainties from environmental and process conditions
  • If sensors are not zeroed at operating conditions, minor additional uncertainties can arise from elevated temperatures and pressures:  ± 0.00008 % of maximum flow per °C and  ±0.0005% of maximum flow per bar.
  • Process temperature effect on density: additional uncertainty of ±0.0005 g/cm³ per °C difference from calibration temperature with standard density calibration and of ±0.00009 g/cm³ per °C difference from calibration temperature with enhanced density calibration. This effect can be mitigated by a simple field density adjustment at operating conditions.
  • Process pressure effect on mass flow: The effect of pressure on flow measurement is 0.0001 % of rate per bar. Compensation is possible by pressure sensor input (analog input or digital write) or manual value entry into the transmitter.
  • Process pressure effect on density: The effect of pressure on density measurement is 0.000075 g/cm³ per bar. Compensation is possible by pressure sensor input (analog input or digital write) or manual value entry into the transmitter.

 

(1) Requires 40 Series transmitter or higher
(2) Requires RHE16 or higher transmitter.
(3) Note minimum operating temperature for SuperDuplex stainless steel is -40°C

Contact us with specification for assessment and availability.

Other wetted materials may be possible for chemical compatibility, lower pressure drop, abrasion allowance, other
application specific requirements. Rheonik can provide nearly any material for the wetted parts.