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Flow Meters - Pneumatic

are available from these manufacturers:
  Hedland Lake Monitors  

 

Hedland Division
Racine Federated, Inc.

General Design Features

OPERATING PRINCIPLE
The Hedland flow meter is a variable area instrument. A precision machined, sharp-edged orifice located within the piston assembly, forms an annular opening with the contoured metering cone. The piston assembly carries a cylindrical PPS/ceramic magnet that is magnetically coupled to an external indicating magnet that moves precisely, in direct response to movement of the piston. A calibrated spring opposes flow in the forward direction. This spring decreases viscosity sensitivity and allows the flow meter to be used in any position, including inverted.
 
Bi-directional flow capability: If required, a reverse flow bypass option is available and is depicted on individual product entries. Note that flow is measured in the forward direction only.
 
Operates in any position: The Hedland in-line flow meter's unique spring loaded variable-area design allows meters to be installed in any position without affecting accuracy. An optional inverted flow scale is also available.
 
Easier to read linear scale: This flow meter is the most readable product in its class. Brightly colored indicators move over the graduated, linear flow scale which contains bold, easy to read numerals and gauge marks. This enhanced resolution virtually eliminates parallax problems associated with competitive, direct reading flow meters.
 
360° Rotatable guard/scale: Hedland's unique design allows the meter to be installed in any orientation without regard to scale direction. Once the meter is permanently installed, the guard/scale can be rotated 360° to optimize readability.
 
Rugged Construction: Flow meters are available in anodized aluminum, brass, T303 and T316 stainless steel, with SAE, NPTF, BSPP, and Code 61 and Code 62, 4-bolt flanged ports. This easy-to-read flow meter is a reliable and trouble-free flow rate indicator, monitoring a variety of liquids and gasses (including aggressive chemicals), under a wide range of pressures, temperatures and rigorous conditions encountered in industrial applications.
 
No flow straighteners or special piping: The Hedland design does not require special plumbing or accessories to stabilize turbulent flow. Flow meters can be installed immediately adjacent to 90 degree ells or other components to provide greatest system design flexibility, while saving installation time and money.
 
Relatively insensitive to shock and vibration: This unique design is inherently less sensitive to shock and vibration than other variable area flow meters. The new, improved coupling forces between the internal and external magnets greatly reduce the chance of decoupling the flow indicator under high flow and pressure transients. The magnetic coupling also eliminates the need for mechanical linkages that wear, loosen and leak over the functional life of competitive meters.
 
To learn more about liquid and gas flow meters from both the technical side as well as the application side click on the following link: Hedland Technical and Application Information.

 
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1000/1500 PSI Flow Meters for Air and Other Compressed Gases

2024 - T351 anodized aluminum body, piston and core and
C360 brass are available in
1/4", 1/2", 3/4", 1", 1-1/4", 1-1/2" NPTF and BSPP rated at 1000 psi
SAE 6, 10, 12, 16, 20, 24 and 1-1/2" Code 62 rated at 1000 psi
3" NPTF and BSPP rated at 250 psi
SAE 28 and 3" Code 61 rated at 250 psi
T303 Stainless body with 2024 - T351 anodized aluminum piston and core is available in
1/4", 1/2", 3/4", 1", 1-1/4", 1-1/2" NPTF and BSPP rated at 1500 psi
SAE 6, 10, 12, 16, 20, 24 and 1-1/2" Code 62 rated at 1500 psi
The extended cap options are available in aluminum, brass and stainless materials for sizes 1/2" to 1-1/2" in NPTF, BSPP and SAE 10 to 24. There are multiple flow ranges in each port size that range from .5 to 2200 SCFM. Pressure drop at 50% flow ranges from 2.0 to 10.75 psi and at 100% flow ranges from 3.13 to 21.25 psi. Temperature range is from -20 to 240°F (-29 to 116°C).
Standard Air and Other Gases Flow Meter Specifications
 
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3500/6000 PSI Test Kits for Air and Other Compressed Gases

2024 - T351 anodized aluminum body, piston and core and
C360 brass are available in
1/2", 3/4", 1", 1-1/4", 1-1/2" NPTF and BSPP rated at 600 psi
SAE 10, 12, 16, 20, 24 rated at 600 psi
T303 Stainless body with 2024 - T351 anodized aluminum piston and core is available in
1/4", 1/2", 3/4", 1", 1-1/4", 1-1/2" NPTF and BSPP rated at 600 psi
SAE 6, 10, 12, 16, 20 and 24 rated at 600 psi
The extended cap options are available in aluminum, brass and stainless materials for sizes 1/2" to 1-1/2" in NPTF, BSPP and SAE 10 to 24. There are multiple flow ranges in each port size that range from .5 to 1000 GPM. Pressure drop at 50% flow ranges from 2.87 to 11.62 psi and at 100% flow ranges from 4.0 to 22.12 psi. Temperature range is from -20 to 240°F (-29 to 116°C).
Pressure gauges are glycerin dampened with 0-160 psi / 0-10 bar range for all test kits. Load valve on 1/2" to 1-1/2" sizes is a nickel-plated brass ball valve with chrome-plated brass ball and Teflon seals. Optional silencer is a 40 micron porous sintered bronze filter with brass body.
Standard Air and Other Gases Test Kit Specifications
 
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1500 PSI Flow Meters for Air / Caustic and Corrosive Gases

T316 stainless steel body, piston and cone is available in
1/4", 1/2", 3/4", 1", 1-1/4", 1-1/2" NPTF and BSPP rated at 1500 psi
T316 stainless steel body, piston and cone for hostile environment is available in
1/4", 1/2" 3/4", 1", 1-1/4", 1-1/2" NPTF and BSPP rated at 1500 psi
3/4" and 1-1/4" BSPP rated at 1500 psi
There are multiple flow ranges in each port size that range from .5 to 1000 SCFM. Pressure drop at 50% flow ranges from 2.0 to 10.75 psi and at 100% flow ranges from 3.13 to 21.25 psi. Temperature range is from -20 to 240°F (-29 to 116°C).
Air and Caustic Gases Flow Meter Specifications

 

Lake Monitors

PNEUMATIC SIZING GUIDE

Pneumatic Monitor Uses and Operating Theory
Lake Monitor's rugged, high pressure pneumatic monitors are designed for permanent installation in compressed gas systems. These products provide a low cost means to measure compressor volumetric outputs, pneumatic tool consumptions and other industrial gas flow rates.

Lake Monitors operate using the variable annular orifice method with compression spring return - the identical method used in our field proven liquid rate monitors. The product's follower, where the measurement is indicated, is magnetically coupled through a high pressure casing to the monitor's internal orifice assembly. The benefits of these design features are:

  • high operating pressure
  • linear displacement of the follower with respect to flow rate
  • high turn-down ratios
  • measuring accuracy within ۮ% FSD
  • operation in any mounting orientation
Lake Monitors are available in three standard materials of construction: aluminum for standard monitoring applications to 600 PSIG, brass for media/material compatibility and operation to 1000 PSIG. Measuring ranges cover 2-12 SCFM through 200-1000 SCFM. Eighteen port sizes from 1/4" through 1-1/2" in NPT, SAE and BSP can be ordered to meet specific plumbing requirements. Lake pneumatic monitors are also available in alarm and transmitter configurations for electronic monitoring applications.
 
Standard Cubic Feet
Lake Monitors are calibrated to measure the flow of compressible media (gases) in SCFM - standard cubic feet per minute. A "standard" cubic foot is defined as a cubic foot of dry air at standard atmospheric conditions: 70°F and 14.7 PSIA (0 PSIG) measured at sea level.
When a standard cubic foot of air is compressed its actual volume will decrease proportionally as absolute pressure increases. For example, a standard cubic foot of air's actual volume will increase by 100% as the air is compressed from atmospheric pressure 14.7 PSIA (0 PSIG) to 29.4 PSIA (14.7 PSIG).
There are three factors that affect the density of a gas: specific gravity, pressure and temperature. Lake Monitors are calibrated for air (specific gravity of 1.0) at 70°F and 100 PSIG. Most low pressure rotameters are calibrated at 0 PSIG and require corrections for use at any other pressure.
Lake products are designed for pneumatic systems where pressures between 90-110 PSIG are used. In these common applications, a Lake monitor with a standard calibration can be read directly without applying corrections.
 
Correction Factors
If a Lake monitor is installed in a system where conditions differ from the standard listed above, correction factors will need to be applied to retain the design accuracy of the monitor. The appropriate correction factor equations are detailed in the Conversion Chart below. To assure the best monitoring accuracy, pressure and temperature measurements should be taken directly at the monitor's inlet port.
 
Special Scales
Special calibrations can be performed by Lake Monitors to correct for the following system characteristics:
  • system pressure
  • system temperature
  • media specific gravity
  • various measuring units (i.e., LPM, LPS, m3/hr, etc.)
  • any combination of the above
Consult the Lake factory or Flo-Products sales for details and prices.
 
Selecting the Proper Monitor
To order a pneumatic flow rate monitor the following information is required:
  • pipe size and port style
  • media (air, nitrogen, argon, etc.) - for material compatibility and specific gravity considerations
  • approximate flow range required
  • system pressure: nominal, maximum, minimum
  • system temperature
Flow Range
Estimating the flow rate in a compressed gas system may seem complicated, but with some research and a few simple equations an educated guess can be made. Two suggested methods are:
 
Method 1
A compressor is typically rated in SCFM output at a certain pressure and efficiency. If the rating cannot be located or is unknown, an estimate of compressor output can be obtained by the following formulas:
  • 1-stage compressors: motor HP/0.179 = SCFM @ 100 PSIG
  • 2-stage compressors: motor HP/0.164 = SCFM @ 100 PSIG
  • 3-stage compressors: motor HP/0.159 = SCFM @ 100 PSIG
Method 2
If all of the potential of a compressor is not being used (the unit cycles on and off) or if flow rate in excess of compressor capacity is being consumed (the compressor cannot meet the demand), a summation of machine usages can be totaled to determine the maximum flow rate. Most machine tools that use compressed air specify the maximum consumption of the tool.

 
CONVERSION CHART
Determine Flow Rates Using Different Pressures & Temperatures
scfm (actual)     =
  scfm (indicated)  
f1 x f2 x f3
 Where f1 = Conversion factor for inlet pressure
f2 = Conversion factor for temperature
f3 = Conversion factor for specific gravity
Table 1 Pressure correction Factor (F1)
OPERATING PRESSURE, psig
psig 25 50 75 100 125 150 175 200 225 250
f1 1.700 1.331 1.131 1.000 .902 .835 .778 .731 .692 .658

f1 = square root of 114.7 ÷ ( 14.7 + psig )
Table 2 Temperature Correction Factor (F2)
OPERATING PRESSURE, psig
°F 10 30 50 70 90 110 130 150 170 190
f2 .942 .962 .981 1.000 1.018 1.037 1.055 1.072 1.090 1.107

f2 = square root of ( 460 + F° ) ÷ 530
Table 3 Specific Gravity Correction Factor (F3)
f3 = square root of Specific Gravity

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Model G Pneumatic In-Line Monitors

These precision, direct-reading flow rate meters are available in aluminum, brass and stainless materials for use in a wide variety of applications. The rugged design operates in systems to 600 PSIG for aluminum and brass models and to 1000 PSIG for stainless steel models, and temperatures to 240°F.
 
FEATURES
Choice of Three Materials of Construction
Select from aluminum, brass or stainless steel to meet system and media requirements.
Unrestricted Mounting
Allows the designer to install the monitor in any orientation; horizontal, vertical or upside down.
Superior Exterior Design
Weather-tight for use outdoors and/or on systems where washdowns are required.
Multi-Use
These versatile monitors are used to verify air compressor outputs and to test pneumatic machinery and tools for proper air consumption.
Rugged and Reliable
These monitors are constructed with all metal pressure vessels, allowing safe, permanent, installation in industrial systems.
High Pressure Operation
The magnetically coupled follower allows operation to 1000 PSIG.
Eighteen Different Ports Available
Standard selection NPT, SAE and BSP ports reduces the amount of adapters required for installation.
Low Cost Precision
Mid-scale measuring accuracy: within ±2.5%. Full-scale accuracy: within ± 4%.
Series G - In-Line Pneumatic Flow Rate Monitor Specifications
 
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Series H / J - High Temperature In-Line Flow Rate Monitor

for 1/4 to 2 inch pipe sizes
These precision, direct-reading flow rate meters are available in aluminum, brass and stainless materials for use with a variety of gases, oils, coolants and water. The rugged design operates in systems to 6000 PSIG and temperatures to 600°F.
 
FEATURES
Multi-Application
Uses include: barrel heating fluids, thermal transfer fluids and non-steam water monitoring.
Three Materials of Construction
Select from aluminum, brass or stainless steel to meet system requirements.
Unrestricted Mounting
Allows the designer to mount the monitor in any orientation; horizontal, vertical or upside down. Does not require inlet or outlet straight plumbing, or require vertical pipe mounting.
Good Viscosity Stability
A thin (0.03"), sharp-edged, orifice provides excellent stability of readings to a minimum of 500 SUS. Uses the variable annular orifice technique with compression spring recovery.
Rugged and Reliable
Designed as a hydraulic service tool, this monitor will provide years of maintenance free performance.
High Pressure Operation
The magnetically coupled follower allows operation to 6000 PSIG and use with opaque liquids.
Twenty-three Different Ports Available
Standard selection of NPT, SAE and BSP ports reduces the amount of adapters required for installation.
Reverse Flow Capability
An option not found in most rotameters and other variable area meters.
Low Cost Precision
Has a measuring accuracy of ±2.5% of full scale in the center third of the measuring range, and ±4% full-scale accuracy over the entire flow measuring range.
Series H / J - High Temperature In-Line Flow Rate Monitor Specifications

 
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