Section 6: Meter operation

 

Reference, Installation, and Operations Manual

June 2013

 

3-9000-743 Rev S

 

Equation 6-15 Pressure-effect strain per unit stress

β

[Dout2

(1 + υ)] + [Din2 (1 – 2υ)]

= -------------------------------------------------------------------------

E ⋅ (Dout2 Din2 )

 

 

where

β =

Dout =

Din =

pipe strain per unit stress (MPaa-1) (StrainPerUnitStress)

outside diameter of the meter or pipe (m) (PipeOutsideDiameter)

inside diameter of the meter or pipe (m) (PipeDiam)

υ

=

Poisson’s Ratio (dimensionless) (PoissonsRatio)

E

=

Young’s Modulus of elasticity (MPaa) (YoungsModulus)

Temperature-effect expansion correction

The meter is capable of correcting the raw volumetric flow rate for the effect of pipe expansion due to temperature changes. Note that for the temperature-effect expansion correction factor to be calculated, the correction must be enabled (via the EnableExpCorrTemp data point) and the flow-condition temperature must be available (i.e., the EnableTemperatureInput data point must be set to ‘Live’(1) or ‘Fixed’(2), see Section 5.6.12). The temperature-effect calculation is shown in Equation 6-16. If the temperature-effect expansion correction factor is not calculated, it is set to 1.0.

Equation 6-16 Temperature-Effect Expansion Correction

ExpCorrT = 1 + [3 ⋅ α ⋅ (Tf Tref)]

where

ExpCorrT =

α =

Tf =

Tref =

expansion correction factor due to temperature (dimensionless) (ExpCorrTemperature)

pipe linear expansion coefficient due to temperature (K-1) (LinearExpansionCoef)

flow-condition temperature (K) (FlowTemperature)

reference temperature for the pipe linear expansion coefficient (K) (RefTempLinearExpCoef)

198

Volumetric flow rate