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Flow

Flow
Flow includes flow transmitters, flow sensors, flowmeters, sight flow indicators, and water meters. Mass flowmeters, controllers, flow indicators and controllers are ideal for measurement of flow rates. Flow switches come as paddle, thermal, piezo, and shuttle/piston.

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
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
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
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
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.