Vertical Pipes - Discharge Height vs. Volume Flow
Volume flow and discharge height from vertical water pipes.
Maximum vertical discharge height for water flow from vertical oriented pipe or tube:
Vertical Discharge - Imperial Units
- coefficient k = 0.96
Vertical Discharge - Metric Units
The maximum height for water discharge from vertical pipe can calculated as:
h = (Q / (5.68 k d2))2 (1)
where
h = discharge height (inches)
Q = flow (gpm)
k = coefficient ranging 0.87 - 0.97
d = diameter of pipe (inches)
- 1 in (inch) = 25.4 mm
- 1 gal (US)/min = 6.30888×10-5 m3/s = 0.227 m3/h = 0.06309 dm3(litre)/s = 2.228×10-3 ft3/s = 0.1337 ft3/min = 0.8327 Imperial gal (UK)/min
Measuring Flow - the Trajectory Method
The discharge from a vertical oriented pipe can be calculated by rearranging eq. (1) to
Q = 5.68 k d2 h1/2 (1b)
The challenge with this flow measurement method may be to measure the height h.
Example - Measuring Flow by measuring the Discharge from a Vertical pipe
The discharge height from a vertical oriented 4 inches pipe is 3 ft (36 inches). With a coefficient k = 0.97 the flow from the pipe can be estimated to
Q = 5.68 0.97 (4 in)2 (36 in)1/2
= 529 gpm
