Floating Arm

Waterfront design and manufacture a float operated discharge arm designed for the use on the outlets from tanks when varying liquid levels are to be accommodated in association with the demand for a controlled rate of gravity discharge.

The series W9000 floating arm is a variable discharge type with single float arrangement. For minimum critical flow level the constant discharge floating arm with either single or twin float arrangement is recommended.

The outlet flange is supplied in accordance with BS450 PN16 rating.


  • Robust Construction
  • Low Maintenance
  • Metal to metal swiveling parts
  • Galvinised Arms
  • Fixing bolts and nuts
  • Options available for twin floats, constant discharge and alternative flange connection

The discharge of water from an orifice can be calculated from the following formula assuming the water has a free discharge.

Q= mA √2gh/ 1000


Q = discharge in litres/sec

A = area in mm

h = height from centre of orifice in metres

V = velocity of issuing water in metres/sec = √2gh

m = Coefficient of discharge – coefficient of velocity x coefficient of contraction

g = 9.81 metres/sec2

The coefficient of velocity of water from a submerged orifice = 0.97. The coefficient of contraction of an orifice comprising a bevel edged thin plate =0.86