What is the syphoning effect?
This phenomenon allows a liquid to flow against the pull of gravity to a higher elevation, before ultimately flowing downwards to a lower level, due to the pressure difference of the atmospheric pressure on the inlet and gravity acting on the contained liquid travelling downwards to the outlet.
Why does this need to be prevented in a dip pipe?
If the flow of process liquid into a dip pipe originates at a lower level than the outlet of the dip pipe, the flow into the vessel stops. There is potential for that same inlet to become an unwanted outlet. Allowing the vessel to be drained in an unchecked fashion through a stopped centrifugal pump etc. causing product contamination.
How do CRP safeguard against syphoning in our dip pipes?
Where customer wish to avoid the potential of syphoning from a vessel we can supply an arrangement of two instrument tees: One placed between the vessel and the dip pipe, the other between the process connection and the dip pipe, these can be connected together with PTFE lined elbows or a PTFE flexible hose. They create the syphon break where gases are drawn from around the top of the dip pipe within the head of the vessel, rather than liquid being drawn up the dip pipe – whilst not affecting its normal use.