Hlt Drip

[redbeard]

just putting together my new electric hlt. has 3 holes :- element, tap & thermometer / sight guage. 1st 2 are fine. for some reason, the last has a drip (about 1 per sec).

ignoring the element (silicon washer), the tap has a hex nipple on the inside with a bsp socket on the outside, with a fibre washer & ss washer on inside & outside. on testing it hasnt leaked.

the the thermo / sight guage via a t piece, connects to a hex nipple on outside, and a lock nut on the insidem with a ss washer & fibre washer in between on inside & out. (see pic).

ive change the lock nut inside & the washer outside. when heating up, the dripping slowed but didnt stop. have tightened lock nut hard. it appears to me that the fibre washers are ok & its the interface between the washer & the hex nipple that is the leak. so should i:
- try to tighten it up more
- add some silicon around washer / nipple
- add another (fibre) washer between ss& nipple
- change the fibre washers for the rubber ones that came with the trutel thermometer

if it was a gas burner, i wouldnt be so concerned, but being an electric hlt, just being paranoid....

suggestions ? (thanks)

 

[NRB]

What about putting an o-ring under the fibre washer? I had a minor leak on one of my taps and this solved the problem for me.

 

[mje1980]

Maybe give the rubber ones a go. I dont know how they will react at high temps, they should be o.k, but you never know. Otherwise, maybe a flat ss washer on the inside between the hex socket and the wall of your hlt will seal better. It's hard to say without seeing it firsthand though.

Good luck, and fingers crossed!

 

[Asher]

Redbeard

Aaaarh! you using anything to stop leaking through the thread?

Asher for now

poor attempt at pirate .... i know

 

[GMK]

Try adding some plumbers tape - as the nipple is not a straight thread but tapered...
This might help.

 

[sluggerdog]

I when to bunnings and grabbed some rubber washers that are for taps, they don't really fit well (little too small) but you stretch them on and they work a treat.

Better then the fibre washers

 

[Borret]

Definately use some plumbers tape, even go for the pink stuff that is temp pressure rated.. Straight (untapered) threads don't naturally seal and even tapered ones are dubious so you need it as a gap filler of sorts. Easy as pie and then you can still use your fibre washers that are fit for purpose as they don't break down under heat like rubber..

Borret

 

[sintax69]

Tape is the answer to this one have the same nipples as in the pic and it was running along the thread also make sure to put the tape on the right direction

 

[Justin]

Yep, plumbers tape as above. But I see another avenue for leak-which I think you alluded to.

I think you said you had on the inside the locking nut, then SS washer then fibre washer. I don't like to use the SS washer. I figured I was getting leaks between the SS washer and the lock nut. I removed the SS washer and just used the lock nut.

Now there are two types of lock nuts available, one is a small minimal design one-the other has a wider flange on it (so it can hold a washer under it). You want the wider flanged one. I know they are available in brass, not sure with SS but I got mine from bunnings (they had both types). The SS washer on the inside isn't really needed on the inside, nor is that fibre washer on the outside (as all your sealing should be done on the inside-but it can't hurt having another on the outside).

You also might want to look at a softer washer than the fibre one on the inside. I've post this before but I use a silcone washer that I made from some cheap silicone bakeware, but I have also cut washers from the 1/2" silicone hose from G&G. It's a bit softer and tends to form a better seal than the fibre washers.

Another trick is to tighten the fitting by turning the outside nipple rather than tightening the nut on the inside of the vessel. This pulls the locking nut and washer straight onto the wall of the keg and seals it. If you try to tighten the inside nut you tend to squish and twist the rubber/fibre washer abit as the locking nut rotates against it and causes a poor seal or if your using an oring will cause it to pop out from behind the nut.

If you tighten using the nipple on the outside of the keg is just works better.

Hope it helps.
Justin

 

[warrenlw63]

I found my seals improved once I adopted the "Johnny works with 2 spanners" routine. Spanner on the inside nut for balancing torque and hold it tight. h34r: Tighten the whole mess from the outside and keep turning until your hands turn blue. Nothing gets through then. :beerbang:

Warren -

 

[BoilerBoy]

I had a problem with leaks along the thread, the fibre washers didn't work it needed something more flexible.
From "Clark Rubber" I bought a piece of 10cm x 4cm food grade rubber strip rated to in exess of 150C for $2 and made up some washers....no problems.

In regards to thread tape Is there a plumbers tape that is suitable for such high temps?

Cheers!

 

[Arkwrights]

It is difficult to see exactly what fittings you have there but if that nipple has a fixed end, if possible that needs to be on the outside as well as an o-ring. (from your plumbers merchant) With the nut on the inside.

If not, you need to have the o-ring on the inside. Either way you should be able to create a seal by tightening those fittings by hand as there is next to no pressure on that joint.

If neither end is fixed (and you have nuts either side) you will always have a leak path along the thread, lots of ptfe tape will probably help but adding a ss washer makes life more complicated by introducing another leak path. Fibre washers are designed to seal against machined surfaces with small surface areas creating a high pressure seal and probably aren’t plyable enough to seal against the relatively rough curved surface of the keg.

(ptfe tape is used on threaded fittings used between-240to+260degC, so will be fine on an HLT)

 

[redbeard]

Thanks for everyones suggestions. For some unknown reason, (brain spasm?) after dis-assembly, i found i had plumbers tape on every thread except the sealing one on the nipple - d'oh. added the tape. then decided to try the brass nut with the large flat face (from bunnins [see sosman wiki]) on the inside with just the fibre washer. tightened this up with 2 spanners, with most of the tightening on the outside, as per Justin's suggestion. did a test and no leaks. the big test will be in a day or so.

as an aside, i had 2 different ss locknuts & a brass one. all screwed on to various depths, with the brass one the 'best'. both the ss would need washers to fill the depth & seal properly. for a hlt, i think the brass will be acceptable.