The
air and gas flowmeters used on this equipment require maintenance
and checks for accuracy. The
accuracy of a flowmeter is plus or minus 2 1/2% of the actual scale
reading, from 25% of scale up to 90% of scale.The
following points must be checked:
- Is the meter zeroed in?
- Is the flowmeter valve in
open position?
- Does the serial number on the nameplate agree with that on the float stop body?
- Is the rod straight?
- Is the float stop body tube straight?
- Is the float level?
- Are gaskets installed
and in good condition?
- Are weights securely
fastened?
- Is the meter clean
internally?
- Is float in proper position in bore?
- Is pressure and specific gravity of gas same on nameplate of
meter?
- A
change in pressure, temperature, and specific gravity of the gas
can cause an error in meter reading.
- Temperature
does not make quite as much difference in reading as does pressure
and specific gravity, although it must not be overlooked.
Making CorrectionsThe
method used for correcting a meter reading is a simple procedure by
the square root law. Solve
for "F". "F"
is the factor by which you multiply the scale reading.
The answer you get will be the actual flow rate.
ACTUAL
FLOW = F x INDICATED
If
you change all 3 conditions, you use the whole formula.
If only one set of conditions change, it is only necessary
to use that portion which applies.
The latest design, materials
and equipment specifications should be obtained from the company
before any reliance is placed on the enclosed since changes may
occur due to product improvement.
