Series RM Rate-Master® Polycarbonate Flowmeter
2", 5" or 10" Scale, Interchangeable Bodies*
The Series RM Rate-Master® Flowmeters are a line of general use, direct reading precision flowmeters suitable for both gas and liquid applications. This Series consists of 2" (51 mm), 5" (127 mm) and 10" (254 mm) scales that can be panel or surface mounted with optional precision metering valves. Within a given Series, the Rate-Master® flowmeter bodies can be instantly interchanged, allowing the piping to remain undisturbed, interchangeability of the ranges, and easy cleaning. *The Rate-Master® flowmeter bodies can be instantly interchanged within the same series scale size, allowing the piping to remain undisturbed, interchangeability of the ranges, and easy cleaning.
NOTE: Effective immediately, the brass valve (-BV) option has been discontinued and the stainless steel valve (-SSV) is the suggested replacement.
NIST CALIBRATION available in Product Configurator.Product Applications
- Medical equipment
- Air samplers
- Gas analyzers
- Pollution monitors
- Chemical injectors
- Cabinet purging
Starting at $47.05
Specifications
- Service:
- Compatible gases and liquids.
- Wetted Materials:
- Body: Polycarbonate; O-ring: Neoprene and Buna-N; Metal parts: SS; Float: SS, black glass, aluminum, K monel, tungsten carbide depending on range.
- Temperature Limit:
- 130°F (54°C).
- Pressure Limit:
- 100 psi (6.9 bar).
- Accuracy:
- RMA: 4%; RMB: 3%; RMC: 2% of FS.
- Process Connection:
- RMA: 1/8"; RMB: 1/4"; RMC: 1/2" female NPT.
- Weight:
- RMA: 4 oz (113.4 g); RMB: 13 oz (368.5 g); RMC: 39 oz (1105.6 g).
- Compliance:
- Meets the technical requirements of EU Directive 2011/65/EU (RoHS II).
- CAUTION:
- Dwyer® Rate-Master® flowmeters are designed to provide satisfactory long term service when used with air, water, or other compatible media. Refer to factory for information on questionable gases or liquids. Caustic solutions, anti-freeze (ethylene glycol) and aromatic solvents should definitely not be used.
Questions
- Question
- How are Dwyer flowmeters properly read?
- Answer
- The flow rate is read at the maximum width portion of the float regardless of shape.
- Question
- 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.
- Answer
- 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 technical service department.
- Question
- Instruction Sheet specs on RM series flowmeters list 100 PSI max pressure, but have seen several RMC flowmeter labels with 35 PSI max pressure rating. Some clarification on pressure ratings please? Thank you.
- Answer
- The older version of the RMC used to have a pressure limit of 35psi because the back plate was assembled from 2 separate pieces. The pressure rating increased to 100psi when we began to stamp the back plate from 1 solid piece.
- Question
- Where is the date code or lot number located on the flowmeter Model RMA-3-SSV?
- Answer
- The date code is on the label.
- Question
- Are your flowmeters (particularly the brass body models) RoHS compliant? Can you provide a statement to that effect?
- Answer
- You can find the RoHS Compliance letter in the tab marked APPROVALS on RM Series.
- Question
- 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.
- Answer
- 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.
- Question
- Is a Dwyer Certificate of Conformance offered with any of the flowmeter models?
- Answer
- 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).
- Question
- Are special ranges available for the Rate-Master® and/or Visi-Float® Flowmeter?
- Answer
- Yes, other ranges are available which are not specified in our catalog. Please feel free to contact Dwyer with questions on these ranges.
- Question
- Is the Rate-Master® or Visi-Float® Flowmeter compatible with any media?
- Answer
- 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.
- Question
- Why are top mounted valves recommended for flowmeters used for vacuum service?
- Answer
- To maintain atmospheric pressure in the indicating bore and therefore preserve accuracy; an inlet restriction would reduce pressure in the bore. This is essentially the opposite situation to outlet back-pressure in a pressure system which increases pressure in the bore and also affects accuracy. Remember that all standard Dwyer flowmeters are calibrated for standard atmospheric pressure and temperature in the bore.
- Question
- What factor is used to correct for different flowmeter inlet pressure?
- Answer
- 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))
Where:
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)
- Question
- What is the calibration frequency, if required, for a RMB flowmeter?
- Answer
- Calibration frequency would be once a year if necessary. We offer a NIST calibration certificate which expires in one year. Contact Customer Service for additional details.
- Question
- Which flowmeters are available with NIST traceability?
- Answer
- 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.
Write Your Own Review
| Model | Description | Availability* | Price | |
|---|---|---|---|---|
| RKA | Regulator kit for RMA or VFA. | 1-3 days* |
$285.85 |
Related Products
