When are picket fence weirs used?
If the liquid rate is high enough not to require splash baffles, but not high enough for a stardard weir, picket fence weirs would be used. For example, liquid rates of 0.10 gpm/inch of weir or less would suggest splash baffles. Liquid rates of 0.10-1.00 gpm/inch of weir indicate picket fence weirs.