Brass Needle Valve?

[grumpthehermit]

Howdy,

I have the Pure Distilling HBS reflux column.

I am happy with the output I am getting but frustrated about my lack of control on the takeoff speed.

It "did" have a 1/4 inch female/female ball valve on it, I have found this to be a pain to control, I have been drawing off anywhere between 12 and 20 minutes for 200ml lots, and struggling to get the exact flow rate I want.

I was at one of the big hardware shops today ( buying Rat Sak, bastard rats in my shed !!! :angry-banghead: :angry-banghead: :angry-banghead: ) and I found one of these.

http://www.blackwoods.com.au/PartDetail.aspx?part_no=08097316

I was not sure of the thread size but took a guess and got it right. :-D

It looked to be all brass, but I pulled it apart at home and found it had a nitrile ( ??? ) o'ring seal on the shaft just above the valve seat / needle inside the valve, I took it off and put it back together again and could not blow air through it so I've left it like that. ( I think it was there because these are rated for high pressure ??? )

Then I took it back apart again and found one more of the same type of seal is also installed up in the top of the tap to seal the thread, it is only exposed when the tap thread is wound all the way down and this was only possible when I screwed the top off the tap. I have left this one installed as I think it needs to be there, and I think it won't be exposed to high ABV??? :?

Does anyone have any thoughts on this???

Cheers
GTH

[MacStill]

Why worry bout nitrile getting in touch with your hooch when the brass may contain some lead anyway ?

[grumpthehermit]

Hey McStill,

Is brass is something that should not be used?

I have read on other posts here that the lead content in brass is not allowed to be about 1%? And from what I read I thought that was considered to be "fine" to use??? :?

If this valve is not suitable can anyone recommend an alternative valve that will fit my rig???

I see the large stainless valves on several photo's of other members rigs on this site, do they have any rubber ( plastic etc .. ) seals inside them or are they all "metal"???

Cheers
GTH

[MacStill]

I guess it's what you feel comfortable with, we eat food every day that prolly has worse chemicals used in it's cycle anyway :?

The safest bet is a Stainless valve with PTFE seals, these valves are considered safe :handgestures-thumbupleft:

Send mrs mac a PM, she'll sort you out with the right one ;-)

[stubbydrainer]

IMHO, brass is left to the relms of cooling lines, I don't like brass in the vapour trail at all,
:twocents-mytwocents:

[grumpthehermit]

Thanks for the feedback.

I'm only only comfortable with being confident that I am not poisoning anyone. :puke-huge:

PM sent. :-D

Reading the brass related posts again I see that the info there only says brass designed for drinking water applications is limited to 1%, industrial could / will be be allot higher I imagine. Therefore, I fu(ked up !!!

Oh well, you live you learn, thanks again.

Cheers
GTH

[Mrs Mac]

Hi GTH,

Just to answer your ?????

It looked to be all brass, but I pulled it apart at home and found it had a nitrile ( ??? ) o'ring seal on the shaft just above the valve seat / needle inside the valve, I took it off and put it back together again and could not blow air through it so I've left it like that. ( I think it was there because these are rated for high pressure ??? )

Nitrile is also known as Buna-N a soft synthetic rubber compound, has good resistance to petroleum-based oils and fuels,water and alcohols. Nitrile also has good resistance to acids and bases, except those with a strong oxidizing effect. Its the same material they make those thin coloured rubber gloves out of, the kind you use for food prep.

You will probably need to replace the o'ring seal that you have taken out, as the needle itself will not compleatly seal and you will more than likely get leakage. You may not have been able to blow air through it but liquid will find a way as the valve was desgined to work with it as a resiliant seated valve not a metal to metal valve. In the valve industry a good solid brass valve is always alot more expensive than stainless.

Inregards to the pressure of the valve this one is rated quite low at about 370 psi in comparrison to most metal seated stainlees steel needle valves rated at 6000psi, but in saying that the higher pressure is not really needed for what you are doing.

Anyways thats my two cents worth...P.M Sent

[grumpthehermit]

Thanks Mrs Mac,

:-D

My guess on the seal was wrong, they are actually "Vitron" o'rings according to Titon who are the manufactures of the valve.

A quick Googe of Vitron gave me even more reading to do ... :shock:

Also the valve is DZR Brass, which I have learnt ( a little too late ... :angry-banghead: :angry-banghead: :angry-banghead: ) means corrosion resistance BUT this also means not only does the valve contain lead ( 3% maybe ) but it also contains arsenic according to the info I read.

Having said that, I'm not going to use this valve, I have read some people "clean" the brass with hydrogen peroxide etc, but this does not sound ideal to me.

Thanks for the PM, will be sending on straight back in a minute or 3.

Cheers
GTH

[Modernity]

You could look at "tinning" the brass with a non-lead soft solder to seal the surface?
this would work like a thick tin plating like they use on copper cooking pots.

[grumpthehermit]

Thanks Mod,

I don't know how practical that would be to actually do ???

In any case I got my new stainless valve today ( thanks Mac and Mrs Mac :-D ) and it's awesome.

I'll chalk the brass one up as a $20.00 learning curve. :angry-banghead:

Cheers
GTH

Also, maybe this post should be moved into the safety folder ??? Just a thought.

[crow]

Hi grump how much did it set you back I've got copper ones but they're no good for this as they are 45' ers :doh: all the inline ones I have are brass

[grumpthehermit]

Gday Crow,

Approx 70 bucks delivered.

If you want a quote PM Mrs Mac, Assuming she can still help out with these?

Thanks
GTH