Introduction

HFV Series is a differential pressure type flow meter which can control the flow rate and measures various fluids, and it provides accurate, repeatable and cost-optimized measurement solution. HFV Series is designed to work in various process applications and is ideal to apply for a wide range of measurement environments. HFV Series has a unique solution outside the scope of traditional technologies due to the hydrodynamic shape of the cone.

Principle of Differential Pressure Measurement

When a cross section area of a pipe is reduced by a diametric change or by the use of flow element which generates differential pressure, the velocity of fluids passing through the pipe is increased across the boundary change area (Continuity Equation), pressure is decreased (Bernoulli Equation) and a differential pressure is generated across the reduction or producer (A1-A2 shown in the diagram at right).

Differential pressure (⊿P) and flow rate (Qv) have a proportional relationship such that . Once differential pressure is measured, flow rate can be determined by this universal relationship.

While this principle is used by other differential pressure flow meters, HFV Series generates a differential pressure by creating an area of reduction using a cone-shaped flow element located on the center line of a pipe section as opposed to a reduced diameter pipe wall or orifice.

Calibration and Discharge Coefficient Determination

All of HFV Series that is manufactured and supplied by Hitrol is calibrated with water at our liquid flow calibration system to determine the Discharge Coefficient (Cd) to verify the performance of the flow meter.

Basic Equations

1.0 Effective Area Ratio (At), Velocity of Approach (E) and Beta Ratio (β) are defined as : 

2.0 Volumetric Flow is defined as :

3.0 Mass Flow is defined as :

= Volumetric Flow
= Mass Flow
= Discharge Coefficient
= Velocity of Approach
= Effective Area Ratio
= Expansibility Coefficient (gas Only)
= Fluid Density
= Differential Pressure (P₁-P₂)

Meter Components

HFV Series is comprised of three primary elements as below.

- Meter Body
Flange, screw and welding type

- Cone Assembly
It is produced by the welding of plate or machining of round bar, and is located at the centerline of the cone meter.

- Pressure Taps
Two pressure taps to read a differential pressure, upstream tap is for high pressure and downstream tap connected to the cone is for low pressure.

HFV Series can be manufactured with various materials such as carbon steel, stainless steel, hastelloy and duplex, etc. to meet requirements for the measurement of various fluids such as liquid, gas, steam and oil, etc.

Components of Flow Measurement System

Specification

Pressure Taps Orientation

Dimension Table

Measurement Range of Liquid Flow Rate (Reference Only)

Measurement Range of Gas Flow Rate (Reference Only)