Siphon Basics

[SUBREW]

Hi All,

Having a little trouble getting the last few litres to siphon from my Keg HLT, pick-up tube, the water doesn't seem to want to go below the tap level.

The 12mm copper pick up tube forms a good seal to the Tap so I don't think air is drawing in... I think my problem is the pipe I have on the outside is approx 20mm.

Is the mismatch in pipe size, internal /external nixing my siphon efforts?

Cheers

SUBREW.

[Kevnlis]

You must be drawing air from somewhere. The larger outer tubing should create a stronger suction.

[buzzkill]

the "out" end of the hose has to be below the pot,mash tun,fermenter,ect. Gravity, its the law.....DOH!!!!

[SUBREW]

You must be drawing air from somewhere. The larger outer tubing should create a stronger suction.

Thanks. The pick up tube is attached with a compression fitting and olive (kinco Style), I'll have another look at that to check all is sweet and air tight... but I wouldn't have to use any thread tape on this type of fitting would I?

the "out" end of the hose has to be below the pot,mash tun,fermenter,ect. Gravity, its the law.....DOH!!!!

Err thanks, yep the end of the hose is below the HLT... gravity does work the same down here thankfully

[Clean Brewer]

Hey mate,

Just put my fittings in a 80 litre pot and have done 2 tests to see what is left after draining, the first I had 1.35 litres left in the pot and the 2nd time I had 2 litres left in the pot...

Not to bad considering the surface area of the bottom of the pot..

[warra48]

If it is a HLT you are trying to drain, why not tip it towards the pickup tube?
That should get most of the water out.
It's what I do with my mash tun, to drain the maximum amount of wort, before batch sparging.

Alternatively, once you know the dead space, why not add that amount of additional water in the first place?

I think you may also have an issue with the size of your pickup tube. I believe the flow rate would be faster through a somewhat smaller tube, and I feel that might help to keep your syphon action going somewhat longer. Might be worth an experiment.