The Dwyer VFC-131-EC is a Visi-Float VFC Series acrylic variable area flowmeter with a 5 in. direct-reading scale for 100 to 700 LPM of air. It has 1 in. female NPT in-line end connections with PVC fittings and an accuracy of 2% of full scale.
Specifications per Dwyer DS-VFC-VFCII EN Datasheet v1 (0826) and Dwyer Bulletin F-48 Rev. 5 (6/20), reviewed 2026-10-18.
The VFC-131-EC measures air flow from 100 to 700 LPM on a scale hot stamped into a body cut and precision machined from solid, clear acrylic. A stainless steel float rides in a precision machined tapered bore against a white background, and the wetted parts are acrylic, Buna-N O-rings, stainless steel metal parts and PVC fittings. It is rated 100 psig (6.9 bar) at 120 °F (48 °C) and mounts vertically with the inlet at the bottom. Gas readings taken at pressures or temperatures other than the conditions the scale applies to are corrected back to those conditions.
Best For
- Direct reading of 100 to 700 LPM air
- Air samplers and gas analyzers
- Pollution monitors
- Cabinet purging
- Medical and laboratory equipment
- Remediation
- In-line installation supported by the system piping
Warranty
Covered by the Dwyer factory warranty. Damage due to contact with incompatible gases or liquids is not covered by warranty. Contact ZOT Supply at sales@zotsupply.com or 855-825-2811 for warranty terms.
Key Features
Direct-Reading LPM Scale
The 5 in. scale reads 100 to 700 LPM air directly. Scales are hot stamped into the plastic, eliminating troublesome conversions and increasing operating life. Gas readings at other pressures or temperatures are corrected to the scale's conditions.
Solid Acrylic Body
Cut and precision machined from a solid, clear acrylic block, allowing complete visual inspection.
Precision Tapered Bore
A precision machined tapered bore enables high repeatability.
White Background
A white background improves float visibility, increasing reading accuracy.
In-Line End Connections
1 in. female NPT in-line end connections with PVC fittings. Installs in-line supported only by the piping, or surface mounts with #10-32 machine screws.
Factory Calibrated
Calibrated at the factory, and normally remains within its 2% of full scale accuracy tolerance for the life of the device. Calibration services are available, including a NIST traceable calibration certificate (-NIST option).
ZOT Supply is an authorized distributor of Dwyer products.
Technical Specifications
| Series | Visi-Float VFC Series |
| Model Code | VFC-131-EC |
| Flow Range | 100 to 700 LPM |
| Scale Media | Air |
| Scale Length | 5 in. typical length |
| Accuracy | 2% of FS |
| Service | Compatible gases and liquids |
| Process Connection | 1 in. female NPT in-line end connections |
| Wetted Materials | Body: acrylic plastic; O-ring: Buna-N (fluoroelastomer available); Metal parts: SS; Float: SS; Fittings: PVC |
| Temperature and Pressure Limits | 100 psig (6.9 bar) @ 120 °F (48 °C) |
| Mounting Position | Vertical, inlet connection at the bottom and outlet at the top |
| Mounting | Surface mount with #10-32 machine screws, or in-line supported only by the piping |
| Fitting Torque | 10 ft-lb (13.56 N-m) maximum; hand tighten only |
| Calibration | Factory calibrated |
| Body Dimensions | 10-1/2 in. (266.70 mm) long x 1-3/4 in. (44.45 mm) wide x 2 in. (50.80 mm) nominal depth |
| Mounting Hole Layout | Three holes for #10-32 machine screws: one 3 in. (76.20 mm) from the bottom of the body, and a pair 1-1/8 in. (28.58 mm) apart located 4-1/2 in. (114.30 mm) above it |
| Weight | 24 to 25 oz (0.68 to 0.71 kg) |
| Compliance | Meets the technical requirements of EU Directive 2011/65/EU (RoHS II) |
| Options (Order Suffix) | -BSPT: BSPT process connections; -NIST: NIST traceable calibration certificate; -VIT: Fluoroelastomer O-rings |
Documentation
Frequently Asked Questions
What flow range does the Dwyer VFC-131-EC measure?
The VFC-131-EC reads 100 to 700 LPM of air directly on a 5 in. scale, with an accuracy of 2% of full scale.
What process connections does the VFC-131-EC have?
The VFC-131-EC has 1 in. female NPT in-line end connections with PVC fittings.
What are the pressure and temperature limits of the VFC-131-EC?
The VFC-131-EC is rated 100 psig (6.9 bar) @ 120 °F (48 °C).
How do I mount the VFC-131-EC?
Mount the VFC-131-EC vertically with the inlet connection at the bottom and the outlet at the top, on a surface and piping free from vibration. For surface mounting, drill three holes for #10-32 machine screws, and install the screws from the rear; screws must not be longer than the panel thickness plus 3/8 in. The meter can also be installed in-line supported only by the piping.
Where should the VFC-131-EC be installed?
Choose a location where the meter can be easily read, the temperature will not exceed 120 °F, and the mounting surface and piping are free from vibration. Arrange the piping so it places no stress on the fittings or the flowmeter body. Avoid strong chlorine atmospheres and solvents such as benzene, acetone and carbon tetrachloride; damage from incompatible gases or liquids is not covered by warranty.
How should the VFC-131-EC be piped?
Approach the inlet with as few elbows, restrictions and size changes as possible, with inlet piping as close to the 1 in. connection size as practical, and make the discharge piping at least as large as the flowmeter connection. On air or gas service, keep the discharge piping as short and open as possible. For vacuum service, keep the inlet piping short and open and install any flow control valve on the discharge side of the flowmeter.
How do I read the VFC-131-EC?
Introduce flow as slowly as possible to avoid damage. Once the float has stabilized, locate the highest point of greatest diameter on the float and align it with the theoretical center of the scale graduation; between graduations, estimate the float position between the two closest graduations.
Does a VFC-131-EC reading need correction for pressure and temperature?
Yes. A gas flowmeter scale applies at a specific set of conditions, and readings taken at other pressures or temperatures must be corrected back to those conditions. Measure the actual pressure and temperature at the flowmeter outlet, or at the inlet under vacuum.
How do I check the calibration of the VFC-131-EC?
It is calibrated at the factory and normally remains within its accuracy tolerance for the life of the device. Re-check it only with instruments or equipment of certified accuracy, not against a similar flowmeter, since minor variations in piping and back pressure can cause significant differences. The flowmeter can also be returned to the factory and checked for conformance at no charge.
What options are available for the VFC-131-EC?
The VFC-131-EC is the standard model with NPT connections and Buna-N O-rings. Dwyer offers these options as order suffixes: -BSPT, BSPT process connections; -NIST, NIST traceable calibration certificate; -VIT, fluoroelastomer O-rings.
How tight should the fittings on the VFC-131-EC be?
Hand tighten only. Do not overtighten fittings or piping into fittings; the maximum recommended torque is 10 ft-lb (13.56 N-m).
What is the difference between the VFC-131-EC and the VFCII-131-EC?
Both read 100 to 700 LPM air with the same 5 in. scale, accuracy and ratings. The VFC-131-EC has 1 in. female NPT in-line end connections with PVC fittings; the VFCII-131-EC has 1 in. male NPT in-line end connections with acetal thermoplastic fittings.
How is the VFC-131-EC cleaned?
Wash the body and parts in a mild soap and water solution; a soft bristle bottle brush simplifies cleaning the flow tube. Avoid benzene, acetone, carbon tetrachloride, gasoline, alkaline detergents, caustic soda and liquid soaps, and avoid prolonged immersion.
- Series:
- VFC
- Product Type:
- Variable Area Flowmeter
- Media:
- Air
- Flow Range:
- 100-700 LPM
- Connection Type:
- Female NPT
- Connection Size:
- 1 in.
- Body Material:
- Acrylic
- Max Pressure:
- 100 psi
- Accuracy:
- 2% FS
- Mounting:
- Vertical
- NIST Calibration:
- Available
