Author Topic: Siphon Nozzle Flow Changes?  (Read 12586 times)

GerryADS

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Siphon Nozzle Flow Changes?
« on: January 18, 2024, 07:26:41 am »
Hey Folks,

I've been running a Delavan 30609-9 (SNA.85) for a few years, and have generally ironed out most of the bugs in my system, however recently I have found that the quantity of oil consumed has drastically reduced for the same air pressure. I've had it apart a good few times over the years, to clean and replace the seal, however the main system remains the same, in that my pre-heat tank sit at 99C via PID, my siphon height is the same 30mm below the nozzle orifice (control keeps level to within 5mm) and my nozzle PID heater holds 75C. Previously I would consume approx. 3.7 Litres per hour at 5psi air pressure, but now I'm down to about half of that? I've checked everything for leaks, replaced all the fittings and pipe work, and new viton seal, all fittings are clean, and there has been no physical changes, but it would appear I've lost vacuum from the siphon effect?
Does the nozzle wear (there is nothing visual, but I don't have another to compare - yet) my oil is filtered to better than 100 microns, but this nozzle has probably seen 12000 Litres use, anybody else experience similar?