1/4-20 thermocouple... grrrrrr

[nrjones89]

My PID stuff just arrived in the mail today and I realized that the K-thermocouple that came with it is too small. Apparently it is not 1/4 but rather 1/4 x 20. No idea what that means. I have a 1/2" NPT coupling and a 1/2" to 1/4" bushing. Is there a stainless bushing I can get, or what can I do to get it in the 1/2 coupling??

 

[ancientmariner52]

1/4-20 = 1/4" thread diameter, 20 threads per inch. I've never seen a pipe thread to machine thread bushing. Are you installing in a thermowell or a 1/2" NPT port?

 

[nrjones89]

I have a 1/2" NPT port, not intending to install a thermowell.

 

[FunkedOut]

https://www.homedepot.com/p/Rutland-1-4-in-NPT-to-1-4-20-Adapter-1439/300981935

you’re gonna need some pipe compound to seal up the 1/4-20 threads. It’s not intended to hold liquid.

 

[nrjones89]

https://www.homedepot.com/p/Rutland-1-4-in-NPT-to-1-4-20-Adapter-1439/300981935

you’re gonna need some pipe compound to seal up the 1/4-20 threads. It’s not intended to hold liquid.

Is there a female to male adapter (thermocouple is male, bushing/coupling are both female.

 

[FunkedOut]

Is there a female to male adapter (thermocouple is male, bushing/coupling are both female.

If you have a pair of females at play, grab a nipple.

 

[nrjones89]

I'm all about the nips, but also the bush

 

[bstacy1974]

If it's one of those cheap thermocouples on Amazon or eBay, I'd just re-order something that will work with your set up. Also, since you're replacing it, ditch the thermocouple and go with an RTD. I retrofitted my kettle to electric last year. Tried to use a thermocouple but the drift was pretty bad and stability was awful. Bought a cheap RTD on Amazon for a replacement. Right out of the box, it was more accurate than the thermocouple.

You'll need something like this.

 

[nrjones89]

Thanks all for replies. I may eventually replace with an RTD. Right now, I'm wondering if I can find a thread adapter at Ace and use pipe compound to seal it??

 

[SleepyCreekBrews]

If you're talking about the K-type that comes with a MyPin PID (see attached) the stainless is so poor, it will rust in short order. They're hard to seal and not designed for brewing, for the price you pay for an adapter, you can get an RTD probe that will fit your system .

 

[nrjones89]

Looks like the same type. I got an Inkbird one. Okay, I am convinced to buy an RTD.

I was also wondering if I should put a voltmeter or ampmeter in the circuit? Anybody else do that?

 

[Bobby_M]

The problem with that probe is that it's not watertight at the probe bolt junction. In a pinch you could squirt some food grade epoxy in between to seal it.