PT100 - Fitting

[Easy Peasie]

A bit stumped here, I have no idea how to fit my pt100 temp sensor in my s/s HLT. Can someone please point me in the right direction. I have been on the TC Direct website and they do have conpression fittings, just not sure which i would need.

Thanks Andy.

 

[BigYin]

My pt100 had screw threads at the base of the probe, I managed to find nuts to fit that and used old O rings from my scuba diving days to seal it.

Having done that I then read of someone using a standard brass tank connector onto a piece of 15mm copper pipe that was blanked off at the end. This pipe protruded into the boiler, and the probe was simply placed in loosely and held in place with some cotton wool, that also insulated the probe's enclosure from outside temps... Since copper is an excellent heat conductor that made good sense.

I searched and searched for a suitable compression fitting, but by the time you step down from 15mm to about 1.5mm the bulk of all the fittings is huge....

If there is a simple fitting out there that would do the job I'd grab it ready for whenever I get a chance to upgrade my boiler....

 

[Northern Brewer]

Hi EP

Here's my PT100 in the side of my HLT

It uses a standard push fit brass tank connector, although you could use a compression fitting if you wanted

Take a length of 15mm brass rod, I got mine from ebay, cut a short length, say about 30mm so it protrudes about 8mm from the tank connector, and file flats on one end of the rod (may be easier to do this beofre you cut it).

Drill the pice of rod all the way through, its brass so its soft and easy to drill, and tap it the same thread as your PT100, mine was M8 but not all are.

Push the rod in the tank connector, wrap some PTFE tape around your PT100 and screw it in using a spanner on the flats of the rod to stop it spinning

Sorted :thumb:

 

[Easy Peasie]

Thanks for the answers guys.
Given me something to think about.

 

[Baldbrewer]

I used compression fittings from BES ltd.
And homemade silicon washers on my mango barrel HLT

 

[MacKiwi]

The brass rod idea is very interesting. I've been trying to decide on how to do the thermowells for a HLT/Boiler build, and this gives me control of both length and internal diameter. My only concern would be how to drill the brass rod - if the probe is quite long, wouldn't this be a bit of a challenge? (I can use a cordless drill but that is about all - I don't have a drill press or anything like that...)

edit : spelling...

 

[MacKiwi]

Never mind, I'm being a bit thick :) The brass rod is drilled right through, so the probe is in the water/wort, and hence the rod is just long enough to go through the tank connector. Drilling that short length isn't too much of a challenge. I had been thinking of the rod as a "pocket" for the probe, but since the probe screws in (with some PTFE tape) it is all water-tight...

Did I get that right?

 

[Northern Brewer]

MK - spot on - the probe is in the tank not in a pocket