and tubing internal diameters 0 005 u2033 and 0 007 u2033 a tube of 0 005 u2033 internal diameter by 60 u2033 long was tested for flow versus pressure drop the measured values are plotted solid line and compared to a poiseuille 39 s law calculation dotted line and compare very well in fig6 poiseuille 39 s law for flow is proportional to the length and to the fourth power of the radius other capillary diameters and lengths are plotted in fig6 as dotted lines this plot indicates the potential flow rates of chemical solution required over the expected process stream flow rates 0 03 ccm to 0 25 ccm are easily accomplished with capillary tubing other flow rates can be accomplished with smaller or larger capillary internal diameters and lengths in addition to the normal chemical injection operation of the system there are two other procedures necessary 1 the initial start up of the system and 2 subsequent refilling of the vessel after an operational period both procedures require the chemical injection subsystem be isolated from the bypass stream by closing valves 8 and 22 both procedures require ambient pressure conditions the initial start up will require filling pressuring fluid volume 13 with high purity water via valve 12 and fill line 11 and then the chemical solution volume 16 with the chemical solution to be added utilizing solution fill line 18 and.