Series VF Visi-Float® Acrylic Flowmeter
Hot-Stamped Scales, Multi-Angle Views of Flow
The Series VF Visi-Float® Flowmeters are a line of direct reading, precision machined, clear acrylic body flowmeters suitable for both gas and liquid applications. The fabrication of the Visi-Float® flowmeters is backed by over 60 years of experience in acrylic instrument machining. This Series consists of 2" (51 mm) and 4" (102 mm) scales with optional precision metering valves.
NIST CALIBRATION available in Product Configurator.
- Medical equipment
- Laboratory equipment
- Air samplers
- Gas analyzers
- Pollution monitors
- Chemical injectors
- Cabinet purging
Models & Ordering
- Compatible gases and liquids.
- Wetted Materials:
- Body: Acrylic plastic; O-ring: Buna-N (fluoroelastomer available); Metal parts: Nickel plated brass standard, SS optional; Float: SS, black glass, aluminum, K monel depending on range.
- Temperature & Pressure Limits:
- Without Valve: 100 psig (6.9 bar) @ 150°F (65°C); 150 psig (10 bar) @ 100°F (38°C); With Valve: 100 psig (6.9 bar) @ 120°F (48°C).
- VFA = 5% of FS; VFB = 3% of FS.
- Process Connection:
- 1/8" female NPT. VFB ranges 85 and 86 have 1/4" NPT back connections or 3/8" NPT end connections. These ranges not available with brass valves.
- Scale Length:
- VFA 2" typical length; VFB 4" typical length.
- Mounting Orientation:
- Mount in vertical position.
- VFA: 4.0 to 4.8 oz (.11 to .14 kg); VFB: 7.2 to 8.8 oz (.20 to .25 kg).
- Agency Approvals:
- Meets the technical requirements of EU Directive 2011/65/EU (RoHS II).
- Bodies are cut and precision machined from solid, clear acrylic blocks allowing for complete visual inspection
- White background allows for better visibility of the float increasing reading accuracy
- Direct reading scales are hot stamped into the plastic eliminating the need for troublesome conversions and increasing product operating life
- Precision machined tapered bore enables high repeatability
- Low installation costs with back or end connection options with metal mounting inserts that can be supported directly by system piping
- Special Multi-Column Visi-Float Flowmeters - Perfect for OEM applications, Visi-Float® flowmeters can be custom made with up to 10 columns in a single block of acrylic plastic. Available with or without valves. Consult factory for more information.
- OEM Specials - Special flowmeter designs can be supplied to meet a wide range of requirements and specific applications. These include: on-off plunger and push-to-test valves, special gas or fluid calibration, special ranges, scales, name brand or other identification. Pointer flags can be furnished for instant visual reference. For specific information, please supply an outline of your requirements.
- -PF Red ABS Plastic Pointer Flag.
- -VIT Fluoroelastomer O-rings.
- -RKA/RK-VFB Pressure Regulator.
|Model Number||Description||Usually Ships*||Price||Order|
|RKA||Regulator kit for RMA or VFA.||Next Day||$263.00||Order|
|RK-VFB||Regulator kit for VFB.||1-2 Weeks||$263.00||Order|
Series VFA - 2" Scale
|EXAMPLE||VFA||1||AT||Series VFA-1-AT Visi-Float® Flowmeter, 2" scale, range .1-1 SCFH air, with aluminum tag.|
|SERIES||VFA||Visi-Float® Flowmeter, 2" Scale|
|.1-1 SCFH Air
.2-2 SCFH Air
.6-5 SCFH Air
1-10 SCFH Air
2-20 SCFH Air
4-30 SCFH Air
5-50 SCFH Air
10-100 SCFH Air
20-200 SCFH Air
.06-0.5 LPM Air
.15-1 LPM Air
.6-5 LPM Air
1-10 LPM Air
3-25 LPM Air
6-50 LPM Air
10-100 LPM Air
6-50 cc/min Water
10-100 cc/min Water
20-200 cc/min Water
.6-5 GPH Water
2-10 GPH Water
3-20 GPH Water
8-40 GPH Water
NIST Traceable Calibration Certificate
Stainless Steel Wetted parts
Stainless Steel Valve*
Series VFB - 4" Scale
|EXAMPLE||VFB||50||AT||Series VFB-50-AT Visi-Float® Flowmeter, 4" scale, range .3-3 SCFH air, with aluminum tag.|
|SERIES||VFB||Visi-Float® Flowmeter, 4" Scale|
|.3-3 SCFH Air
2-20 SCFH Air
4-40 SCFH Air
10-100 SCFH Air
15-150 SCFH Air
20-200 SCFH Air
100-1000 cc/min Air
.2-4 LPM Air
1-10 LPM Air
1-20 LPM Air
3-30 LPM Air
4-40 LPM Air
.5-12 GPH Water
6-60 GPH Water
2-30 cc/min Water
1-20 GPH Water
6-40 GPH Water
.2-2 GPM Water
.6-5 GPM Water
.3-3 SCFM Air
1-10 SCFH Air
2-20 SCFH & 0.5-9.5 LPM Air
10-100 SCFH & 6-48 LPM Air
15-150 SCFH & 5-70 LPM Air
40-200 SCFH & 20-95 LPM Air
0.5-12 GPH & 0.04-0.74 LPM Water
1-20 GPH & 0.1-1.3 LPM Water
1-10 SCFH & 0.6-4.8 LPM Air
0.6-5 SCFH & 0.3-2.5 LPM Air
6-50 SCFH & 3-23 LPM Air
10-100 GPH & 0.5-6.5 LPM Water
*Valve is designed for flow adjustment only, not intended to be used as an open/shut-off valve.
Product Data Sheet
- How are Dwyer flowmeters properly read?
- The flow rate is read at the maximum width portion of the float regardless of shape.
- For the VFA-44-BV product, what is the minimum flow that I can reliably control with a pressure head of up to 4 bar? Will the needle valve function properly at that pressure/flow combination? Thank you.
- At a pressure of 4 bar (58 psi), the needle valve should function properly and provide reliable control over the whole range, which is 8-40 gallons of water per hour.
- Is a Dwyer Certificate of Conformance offered with any of the flowmeter models?
- A standard Dwyer Certificate of Conformance can be offered with all Dwyer Mini-Master®, Rate-Master®, and Visi-Float® flowmeters on all water ranges (or other compatible liquids).
- Are special ranges available for the Rate-Master® and/or Visi-Float® Flowmeter?
- Yes, other ranges are available which are not specified in our catalog. Please feel free to contact Dwyer with questions on these ranges.
- Is the Rate-Master® or Visi-Float® Flowmeter compatible with any media?
- The Rate-Master® Flowmeter is manufactured from a polycarbonate plastic and the Visi-Float® Flowmeter is manufactured from acrylic. Compatibility charts need to be reviewed to determine if these materials of construction are compatible with your media.
- What factor is used to correct for different flowmeter inlet pressure?
- If the flowmeter is exhausting to atmosphere, no correction factor is needed. If back-pressure is present due to downstream plumbing or restrictions, this error can be corrected utilizing the conversion curves in our full-line catalog or the following equation.
Pressure: Q2 = Q1 x √((P1 x T2)/(P2 x T1))
Q1 = Observed Flowmeter Reading
Q2 = Standard Flow Corrected for Specific Gravity
P1 = Actual Pressure (14.7 psia + Gage Pressure)
P2 = Standard Pressure (14.7 psia, which is 0 psig)
T1 = Actual Temperature (460 R + Temp °F)
T2 = Standard Temperature (530 R, which is 70°F)
- Which flowmeters are available with NIST traceability?
- All Dwyer Mini-Master®, Rate-Master®, and Visi-Float® flowmeters are available with NIST traceability on all air ranges except for RMA-1, RMA-11, RMA-150, RMA-151, VFA-1, VFA-21 and VFB-60 models.
- I Need a variable area flowmeter that will work with hydrogen, will any of the poly bodied units like the RMA/B work, or do I need a glass vial?
- Yes, can use the Series RM or VF with hydrogen.
- I am looking to use an "Air" flowmeter RMA-6-SSV to monitor CO2 flow. I am wondering if there are are any concerns or correction factors I need to apply.
- A specific gravity correction factor will need to be considered when monitoring other gases with a meter calibrated for air. The correction factor equation is as follows:
Q2=Q1 x sqrt (1/S.G.)
Where: Q1= Observed Flowmeter reading
Q2= Standard Flow Corrected for Specific Gravity
1= Specific Gravity of Air or Water
S.G.= Specific Gravity of media being used in flowmeter originally calibrated for air or water.
This equation can be found in the beginning of the Flow section in the catalog. Alternatively, special ranges and scales can be provided; for specific information please contact our customer service department.
For further information, see our "Tech & Specs" Video Blog: Fix your Flow... Specific Gravity and Pressure Corrections for Variable Area Flowmeters (Episode 4), in Dwyer's Video Library.
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