The HVT-RF-Halmi Rectangular Flow Meter...rectangular venturi meters of the various competitors, expressed as a percentage of differential. Figure 2 also displays the headloss for

The HVT-RF-HalmiRectangular Flow Meter

Product Data Sheet Document 2021 - Rev02

Flow Measurement in Large Rectangular ConduitsWithout Tests!Model

P R I M A R Y F L O W S I G N A L , I N C .T H E L E A D E R I N R E L I A B L E F L O W M E A S U R E M E N T

© 2006 - Primary Flow Signal, Inc. - All Rights Reserved

SHOWING STANDARD 3.0” REMOTE SEAL PRESSURE PORTS.

SHOWING CHEMICAL TEE PRESSURE PORTS.

Accuracy:

Headloss:

Upstream Piping Effect:

Downstream Piping Effect:

+/- 0.75% of actual flow rate, statisticallysubstantiated to 95% confidence level.+/-0.50% or better available with modeltesting.

Less than half the headloss of circularASME venturi tubes (with 15 includedrecovery cone angle.)

O

Known.

None, even with flow control butterfly-valve close coupled to recovery section.

6’ x 5’ HVT-RF Halmi Rectangular Venturi weldment pressurevessel type meter. Accuracy +/-0.50% of actual rate.

The PFS, Inc. research team has succeeded indemolishing the barrier that has previously separatedthe high accuracy and low headloss achieved bycircular HVT meters from accuracies and head losseswhich are typical of rectangular flow venturi metersmade by competitors. Now, the well establishedperformance characteristics of the world-class HVT-Halmi Venturi meter for cylindrical lines has beenadapted, scientifically, to the unique demands imposedby rectangular flow measurement applications.

Extensive research conducted on the performance ofcompetitor’s devices has enabled our impartial andpenetrating comparative analysis with the demonstratedperformance superiority of the HVT-RF HalmiRectangular Venturi design.

Please compare what the HVT-RF Halmi RectangularVenturi meter can do compared to others:

Figure 1 shows discharge coefficients obtained by flowcalibrations on so-called rectangular venturi metersaccumulated over the past three decades, designedand propounded by four different manufacturers.

All of these “rectangular venturi meters” were expectedto have coefficients between 0.98 and 0.99. As figure 1demonstrates, facts contradict these expectations in allbut one design, the HVT-RF.

The manufacturers also hoped that there would be noBeta effect. The laboratory evidence suggests that inall cases except the HVT-RF, their coefficients are notindependent of Beta.

One of the competition’s most significant oversights hasbeen their failure to correctly establish Line Size effecton their designs. As a result, the inevitable extrapolationof coefficient to line sizes not specifically calibratedcannot be scientifically justified.

Analyzing figure 1 demonstrates that the HVT-HalmiRectangular design secures the following performance:

0.9900 Coefficient value (Identical to the HVT-circular design.) Applies to all line sizes and allBeta ratios.

An accuracy of +/-0.75% of the coefficient with astatistical substantiation of +/-0.46%, at 95% (twicestandard deviation) confidence level.

Reliability, which a single line size model testcannot provide. Figure 1 shows the HVT-RF tests ofmultiple beta ratios and two different line sizes.

Coefficients of Discharge that is linear above pipeReynolds number of 75,000.

DISCHARGE COEFFICIENT - C

CONTINUED NEXT PAGE

HEADQUARTERS LOCATION:

800 Wellington Avenue Cranston, RI 02910, USA

Toll Free: 1-877-737-3569 Ph: 401-461-6366 Fx: 401-461-4450

PFS INDUSTRIALPRODUCTSGROUP:7136 SouthYale, Suite300Tulsa,OK 74136, USA

Ph:918-481-3210 Fx:918-481-3205

http://www.primaryflowsignal.com

The HVT-RF-HalmiRectangular Flow MeterProduct Data Sheet Document 2021 - Rev02Page 2 of 4



HEADLOSS CONSIDERATIONS

C - UPSTREAM and DOWNSTREAM PIPINGEFFECTS

Figure 2 shows the headloss exhibited by therectangular venturi meters of the various competitors,expressed as a percentage of differential.

Figure 2 also displays the headloss for circular ASMEventuri meters as well as HVT-Halmi rectangularventuris obtained by flow tests. The data clearly showthe superiority in energy recovery of the HVT-Rectangular Venturi design.

We conducted selective upstream piping effect testswhich indicate that the circular HVT upstream pipingeffect data can be utilized to accurately estimate theupstream piping effects on HVT-Rectangular coefficient.

We also conducted tests to establish the effects of arectangular butterfly valve installed on the recoverysection of the HVT-Rectangular venturi.

No appreciable effect was revealed either on thecoefficient or on the flow control performance.

The most striking contrast that permits appreciation ofthe superiority and achievements of PFS, Inc. in thisregard is to examine the words of our competitorreviewing the drawing of our 0.41 Beta HVT-RF (seefigure 2) in a communication to our customer:

“...Engineering is flawed since the specified 13”headloss cannot be met with a 0.408 Beta ratio.Whoever engineered the PFS system apparentlydoes not understand how to calculate headlossin a rectangular meter.”

“...We calculated the proper headloss of the PFSmeter as 14.1” or 22% (of the differential)...”

“...We have numerous rectangularcalibrations...Example: a (156” x 60”) x (68.6’ x60”) ---Beta 0.6631 -- meter had an 18% loss.”

NOTE:

NOTE:

See figure 2. The PFS HVT-RF model testshowed 8.9% headloss (of differential) for subjectmeter.

See figure 2. A PFS HVT-RF with identicalBeta ratio has 4% loss!

PFS-HVT HalmiRectangular Venturi

ASME Circular Venturi with15 Recovery Cone.

O

27.6%51.6%47.8%



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The HVT-RF-HalmiRectangular Flow Meter

Product Data Sheet Document 2021 - Rev02Page 3 of 4



SHOWING STANDARD 3.0” REMOTE SEAL PRESSURE PORTS.

“...It is a well known fact that rectangularventuri meters always have a higher headlossthan circular ones.”

Pressure Vessel Type Weldment HVT-RF Halmirectangular venturi.

Component TypeHVT-RF Halmirectangularventuri.

Summary

Figure 3a illustrates the interior and exterior of a 6ft x5ft Halmi rectangular meter. This meter measures flowwith an accuracy of +/-0.50% (not the standard +/-0.75%) because the effect of upstream piping wasestablished by properly designed model tests as shownin figure 3c.

Figure 3c illustratesa 10ft x 10ft HVT-RF Halmirectangular venturiunder construction.Primary FlowSignal, Inc.

provides the inlet and throat components fabricated ofsuitable materials, along with construction drawings,specifications and instructions for the construction work,as well as on-site inspection and management, asrequired. The result is a top quality cast-in-place meterthat will perform to the high standards for which PFS,

Inc. has become recognized, worldwide.

The HVT-Halmi rectangular venturi design principle,with its inherent geometric similitude, coupled with “PFSFlow Metering Know-How” results in rectangular flowmeasurement that can now obtain +/-0.50% accuracy,no large line size limitations, and no “bad” pipingeffects, since they can be eliminated by properlydesigned scale model tests.

NOTE: See figure 2. Compare the ASME circularheadloss curve to the PFS-HVT-RF rectangularventuri headloss curve.

APPLICATIONS

CONTINUED NEXT PAGE

Figure 3d Modeltests must be pro-

perly designed withhydraulic and geo-

metric similitude.By using “PFS-Know-How” the

accuracy obtainedon these modeltested HVT-RFinstallations is

+/-0.50% of actual,including piping

effects.

Figure 3a 6ft x 5ft HVT-RF with +/-0.50% accuracy.

Figure 3b 6ft x 5ft HVT-RF exterior view.

Figure 3e Model test underway at calibration facility.

Figure 3c 10ft x 10ft HVT-RF under construction. PFS supplies all fabri-cated meter components together with construction drawings, specifica-tions and instructions, and management and inspection, assuring a suc-cessful cast-in-place meter installation, with optimum performance.



Toll Free: 1-877-737-3569 Ph: 401-461-6366 Fx: 401-461-4450


Ph:918-481-3210 Fx:918-481-3205


HVT-CI Halmi Cast Iron Venturi Flow Element

HVT-FV Halmi Fabricated Venturi Flow Element

HVT-PI Halmi Plastic Insert Venturi Flow Element

HVT-SM Halmi Sealed Metering System

HVT-FC Halmi Rate of Flow Controller

HVT-BC Halmi Bi-Directional Flow Meter

Flow Direction(Paddle) Switch

PFS-HN Halmi Nozzle-Flume/Open Channel Flow

PFS-HP High Performance SMART Transmitter

PFS-FM PFS FlowMasterTM

3MV-STD3-Valve Manifold for All Applications.

Turbine MetersMeters and Monitors

PFS-Construction & Rehab Management

PFS-WM PFS WedgeType Flow ElementTM

APPLICATIONS:

Highly Viscous LineFluids.

Contaminated Line Fluids.

Low pipe ReynoldsNumber situations.

Available in wide range ofline sizes and endconnections.

Special materials foraggressive line fluids,high pressure and/ortemperature.

PFS-ASMENozzles, Orifice Plates, Venturis, Etc.

-ASME

-ISO

-ISA

-OTHER

Look to Primary Flow Signal, Inc.for Reliable and Innovative Solutions

for your FlowMeasurement

Needs!

Venturi Flow Meters

Rate of Flow Controllers

Orifice Plates and Flanges

Turbine Flow Meters

Positive DisplacementFlow Meters

Instrument Valve/Manifolds

Monitors, TransmittersFlow Computers

Accessories andSpecialty Items

PFS WedgetypeTM

CONTACT US IF WE CAN ASSIST YOU WITHANY OF YOUR FLOW MEASUREMENTREQUIREMENTS.

AN EXTENSIVE STAFF OF ENGINEERS ANDSPECIALISTS IS AVAILABLE SYSTEM-WIDE TOCOURTEOUSLY, KNOWLEDGEABLY ANDEFFICIENTLY PROVIDE APPLICATION ANDDESIGN GUIDANCE.





Toll Free: 1-877-737-3569 Ph: 401-461-6366 Fx: 401-461-4450


Ph:918-481-3210 Fx:918-481-3205


Documents

The HVT-RF-Halmi Rectangular Flow Meter...rectangular venturi meters of the various competitors, expressed as a percentage of differential. Figure 2 also displays the headloss for