VFF size Flow Meters














Information about the VFF meter
Positive displacement flowmeters, also known as PD meters, measure volumes of fluid flowing through by counting repeatedly the filling and discharging of known fixed volumes. A typical positive displacement flowmeter comprises a chamber that obstructs the flow. Inside the chamber, a rotating/reciprocating mechanical unit is placed to create fixed-volume discrete parcels from the passing fluid.
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In the VFF the rotor is basically a disc shape with an annular groove on its underside capable of holding and transporting flow from the chamber inlet to the outlet. Some fluid is also transported in a cavity formed between the rotor outside wall and the chamber wall. A centre ‘peg’ under the rotor is constrained to run in a circular groove in the body. A web (or plate) in the body is engaged with a slot in the rotor and this modifies the rotation to that of an oscillation as flow passes. It is this oscillation that produces the compartmentation of the fluid into ‘positively displaced pockets’. The top of the rotor is equipped with a powerful magnet directly above the ‘peg’ that is on the underside and so this also has a circular path which allows it to engage and disengage a reed switch sensor located in the top cap above.
VFF4, VFF8
The VFF range started in 1986 with the original VFF4 size rated to 4 litres per minute. The VFF8 has a rotor with twice the height and was therefore rated to 8 l/m. Subsequently materials have been improved and the new ratings increased to 400 and 800 litres per hour.
Typical Applications
Chemical Injection | Hydraulics | Wax Dispersant |
Corrosion Inhbitor | Subsea Control fluid | PIB |
Scale Inhibitor | Subsea flow | Ashalphtene Dispersant |
- TECHNICAL
- FLOW RATE
- CONNECTION
- MATERIAL
- DISPLAY
- DOWNLOADS
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Key Features
Compact | Single Moving Part | Pressure independent measurement |
No straight lengths | Large Viscosity range, from methanol upwards | Ultra High Pressure Capability (35,000psi, 2500bar if required) |
Very Low Flow Measurement | Measures pulsing flow accurately | Low Maintenance |
Tolerant of particulate up to 100+ microns | Preserves Molecular Integrity of fluid | Highly Durable |
Low pressure drop (<0.1 bar typical) | Proven since 1986 |
Technical Specifications VFF range
Flow ranges
VFF4 | 0-400 l/hr | More detail in FLOW RATE tab |
VFF8 | 0-800 l/hr | More detail in FLOW RATE tab |
Accuracy | ±1% of reading, requires linearisation. | Provided by all Litre Meter instrumentation. |
Pressure Rating | Dependent on Connection size and rating | More detail in CONNECTION tab |
Temperature Rating | -40°C - +100°C dependent on material and instrument; higher temperature possible. | |
Viscosity Range | 0.5 - 100,000 cP or greater. | More detail in FLOW RATE tab |
Recommended Filtration | A 100 micron filter is advisable for 100% long life serviceability. | |
Dimensions | Refer to K0003 drawings | Link in DOWNLOADS tab |
Pressure Balanced Chamber (PBC)
This describes the rotor and the chamber in which it rotates. It's a separate item that can be removed for inspection and calibration. A side benefit is that it enables pressure independent measurement.
Key Benefits
No distortion of the chamber at higher pressures
- No measurement inaccuracy due to pressure
- Enables selection of optimal materials for the chamber to match the rotor i.e. PVD coated stainless steel.
- Enables selection of optimal materials for the pressure vessel. i.e. super duplex stainless steel
- Enables construction of a duplex bodied flowmeter – duplex material does not lend itself to the tolerances required in machining
Flow Ranges and viscosity
Minimum Flow Rate Measurable at Viscosity, L/hr | |||||||||
1 cP | 1.5 cP | 2.5 cP | 7.5 cP | 10 cP | 25 cP | 50 cP | 250 cP | ||
VFF4-400 L/hr Max | Standard | 14 | 7.4 | 4 | 3.2 | 2.4 | 2 | 1.5 | 1.2 |
Low Flow | 9 | 5 | 2.7 | 2.1 | 1.6 | 1.3 | 1 | 0.8 | |
VFF8-800 L/hr Max | Standard | 45 | 25 | 8 | 6.4 | 4.8 | 3.9 | 3 | 2.4 |
Low Flow | 30 | 16.5 | 5.3 | 4.3 | 3.2 | 2.6 | 2 | 1.6 |
Standard Connections
Threaded
Pressure Rating, bar | Description |
530 | 1/2 inch female NPT |
500 | 3/4 inch female NPT |
1380 | 9/16″ Autoclave Engineers Medium Pressure female fitting (SF562CX20) |
1380 | 3/4″ Autoclave Engineers Medium Pressure female fitting (SF750CX20) |
Wafer
RF, Raised Face
Flange Rating | Nominal Pipe Size |
ANSI 150 | 3/4″ or 1″ |
ANSI 300 | 3/4″ or 1″ |
ANSI 600 | 3/4″ or 1″ |
ANSI 1500 | 3/4″ or 1″ |
ANSI 2500 | 3/4″ or 1″ |
RTJ, Ring Type Joint
Flange Rating | Nominal Pipe Size |
ANSI 150 | 1″ |
ANSI 300 | 3/4″ or 1″ |
ANSI 600 | 3/4″ or 1″ |
ANSI 1500 | 3/4″ or 1″ |
ANSI 2500 | 3/4″ or 1″ |
Hub
Graylock
Techlok, Galperti, Destec upon request
Higher pressure ratings achievable with F51
Custom: Call for further options
‘Flanged’: Call for further options
ANSI 10,000:Call for further options
Pressure Rating, bar | Description |
706 | 1GR4 Grayloc Hub Connection |
656 | 1GR5 Grayloc Hub Connection |
496 | 1GR7 Grayloc Hub Connection |
290 | 1GR11 Grayloc Hub Connection |
Materials Coding Body and Cap
Code | Material |
SS | 316 Stainless Steel (UNS S31603) |
44 | F44 6Mo SS Body & Cap (UNS S31254) |
51 | F51 Duplex Body (UNS S31803) & F44 Cap (UNS S31254) |
53 | F53 Super Duplex Body (UNS S32750) & F44 Cap (UNS S31254) |
55 | F55 Super Duplex Body (UNS S32760) & F44 Cap (UNS S31254) |
HA | Hastelloy Body & Cap (UNS N10276) |
TI | Titanium (UNS R50400) |
Code | Manufacturing Method |
BB | Body ‐ Not Forged / Cap ‐ Not Forged |
FB | Body ‐ Forged / Cap ‐ Not Forged |
FF | Body ‐ Forged / Cap ‐ Forged |
CS | Custom Specification |
Materials Coding Chamber & Rotor
Code | Chamber | Lid | C/L Coating | Rotor | R Coating | Magnet | Description |
AP | N60 | N60 | PVD | N60 | PVD | Encapsulated 316 | PVD Coated N60 Chamber and Rotor |
TA | Ti5 | Ti5 | PVD | Ti5 | PVD | Encapsulated Ti | PVD Coated Titanium Chamber and Rotor |
TC | Ti2 | Ti2 | none | Carbon | none | Encapsulated Ti | Titanium Chamber and Carbon Graphite Rotor |
Call for further options
Materials Coding Seals
Code | Material |
V | Viton |
N | Nitrile |
P | PTFE Encapsulated Viton |
E | EPDM |
NAED | Nitrile non explosive NBR |
K | Kalrez |
CH | Chemraz |
MV | Inconel/Viton |
MP | Inconel/PTFE Encapsulated Viton |
MK | Inconel/Kalrez |
MCH | Inconel/Chemraz |
MN | Inconel/Nitrile |
ME | Inconel/EPDM |
Display for VFF meters
FlowPod
- Exd‐ CSA(US): Class1 Div1 (B,C,D); Class 1, Zone 1, AEx d IIC T5 Gb
- CSA(CAN): Class1 Div1 (B,C,D), Exd IIC T5 Gb, Tamb -20°C to +75°C
- ATEX: Ex db IIC T5, Ex tb IIIC 80°C
- IECEX: Ex db IIC T5, Ex tb IIIC 80°C
- IP 66/IP68 dual certified
- Ambient temperature: ‐20 to +75°C
- 2 or 4 wire 4‐20mA HART 7 programming and monitoring
- Compact lightweight 316 stainless steel housing
- Rotatable through 360° for optimised viewing angle
- 2 VFF sensing options ‐ standard and hi‐res ‐ both with bidirectional sensing
- Removable LM‐MC storage card for data logging & offsite programming
- Resettable and non‐resettable Totaliser
- Batch control
- Power: 12 – 30 Vdc
Fluidwell
- Safe area or ATEX / IECEX / FM / CSA Exia
- 2 wire 4‐20mA HART output (HART is optional)
- Material: GRP or Aluminium
- IP 67
- Ambient temperature: ‐40 to +70°C
- Rotatable through 360° for optimised viewing angle
- Resettable and non‐resettable Totaliser
- Batch control
- Power: 12 – 30 Vdc, Battery or Loop powered
VRGS
- Safe area or ATEX II 2G Ex ia IIC T4 Gb
- 2 wire 4‐20mA HART output (HART is optional)
- Material: 316 SS
- IP 66/IP67
- Ambient temperature: ‐40 to +120°C
- Rotatable through 360° for optimised viewing angle
- Resettable and non‐resettable Totaliser
- Power: 15 – 30 Vdc,can be Loop powered