PRV

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rgreen2002
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PRV

Post by rgreen2002 »

So more and more I have been wondering about the pressure buildup in my steam mashing rig. I have a side vent above the barrel and the steam wand that I use a cork as a pop off valve for right now but I was looking for something better. I am not very versed in steam pressure release valves and I was wondering if I can use this type of valve:
PRV.jpg
Here are the specs: https://www.amazon.com/Kingston-125SS-B ... B006U4I1MO" onclick="window.open(this.href);return false;" rel="nofollow

I was planning on a regular PRV like one on a water heater but for 5 or 10 psi but this caught my eye.
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Blarney Stoned
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Re: PRV

Post by Blarney Stoned »

Go for it as long as you are sitting by your rig. Should it start blowing cut the power. Wouldn't be a bad idea to have a ball valve somewhere on your boiler to evacuate the pressure quickly should that happen..
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Re: PRV

Post by Hank Reardon »

Personally, I would purchase a factory set relief valve rather than something I can "set". Unless you have a method to calibrate, it is a risk worth considering. Where I live, a "certified boiler" prv is not adjustable, nor is it something that is permanent. It has to be replaced annually.

Anyway, I suggest a factory set <8lb psi. Amazon has them.

Good luck.
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Re: PRV

Post by Blarney Stoned »

I don't see in the OP's listing where it says it's adjustable which would be a spring shim or a different rated spring in this particular instance.
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Re: PRV

Post by Hank Reardon »

Blarney Stoned wrote:I don't see in the OP's listing where it says it's adjustable which would be a spring shim or a different rated spring in this particular instance.
For you to see what you require, you would have to read the description on amazon. It reads something like this:


"The Kingston Model 125SS Safety Valve is precision machined with hard seat. This pop-style safety valve is constructed from brass and features a stainless steel ball on a brass seat. Set pressure range 5 to 300 psi (5 psi increments only). Maximum temperature 400°F."

That may be not considered an OP post, but is certainly worthy of consideration. I do not speak for another here, but I would buy a factory set relief valve.
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rgreen2002
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Re: PRV

Post by rgreen2002 »

Hank Reardon wrote:
Blarney Stoned wrote:I don't see in the OP's listing where it says it's adjustable which would be a spring shim or a different rated spring in this particular instance.
For you to see what you require, you would have to read the description on amazon. It reads something like this:


"The Kingston Model 125SS Safety Valve is precision machined with hard seat. This pop-style safety valve is constructed from brass and features a stainless steel ball on a brass seat. Set pressure range 5 to 300 psi (5 psi increments only). Maximum temperature 400°F."

That may be not considered an OP post, but is certainly worthy of consideration. I do not speak for another here, but I would buy a factory set relief valve.
You are correct Hank. It's why I put the Amazon link up there. It is adjustable. Thanks for the input gents!
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Re: PRV

Post by rad14701 »

You surely don't want your release pressure to be too high but beyond that you really need an extra large dump circuit for the steam... Remember, one ounce of water fills 1600 times more volume once it becomes steam... Even a large dump circuit can blow steam for more than a few seconds... A small hole would not allow enough steam to dump fast enough to keep the pressure from continuing to build... You don't want to end up with a catastrophic failure like the one that happened at the craft distillery last year that killed one and permanently maimed another...
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Re: PRV

Post by Blarney Stoned »

Considering the size of the OP's boiler this would be an appropriate sizing should an over pressure situation arise for proper evacuation.

I cheated and took the part # off the valve on my 40 gallon residential water heater.



http://www.ebay.com/itm/Apollo-Valve-13 ... 2233997008" onclick="window.open(this.href);return false;" rel="nofollow

Edit:

Cheaper !!!

https://www.amazon.com/Apollo-Valve-13- ... B008837YUK" onclick="window.open(this.href);return false;" rel="nofollow
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shadylane
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Re: PRV

Post by shadylane »

Just my opinion
It doesn't take very much pressure on a steam mashing rig, to blow steam bubbles into the bottom of a 2 foot tall mash bucket.
24" water pressure is around around 1 psi.
Use a 6 foot tall manometer or water trap for a PRV. Any vacuum or pressure above 3PSI would blow or suck the water out.
Cheap, simple, accurate and 100% effective.
If you buy a store bought PRV, I'd recommend using a 1/2" or bigger.
An 1/8" PRV might flow enough to keep a keg still, with a 5kw heater from going boom.
But only if it doesn't get plugged up :shock:
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Re: PRV

Post by rad14701 »

shadylane wrote:Just my opinion
It doesn't take very much pressure on a steam mashing rig, to blow steam bubbles into the bottom of a 2 foot tall mash bucket.
24" water pressure is around around 1 psi.
Use a 6 foot tall manometer or water trap for a PRV. Any vacuum or pressure above 3PSI would blow or suck the water out.
Cheap, simple, accurate and 100% effective.
If you buy a store bought PRV, I'd recommend using a 1/2" or bigger.
An 1/8" PRV might flow enough to keep a keg still, with a 5kw heater from going boom.
But only if it doesn't get plugged up :shock:
And just as long as you don't let the narrow concentrated blast of steam cut you in half...!!! :esurprised: A manometer is a far safer solution because you can see what's happening before it happens in a bad way... :thumbup:
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Re: PRV

Post by rgreen2002 »

I love this place...it's like college! I mean along with the the drinking and out of the box thinking... there is course work too. Recently finished Fermentation 101 and 201, Distillation 101 and now onto Physics... :mrgreen:

Thanks gents... always appreciate a reply. The more I think about this the more wonder... that pushes me back to the steam threads to reread and then offsite....to read a little more.

This is my setup for steam mashing:
An older pic but the basic design is the same.
An older pic but the basic design is the same.
My wand is the SS mesh cover mentioned here many times before:
Again, old pic.  Replaced the hose clamps.  Considering solder soon...
Again, old pic. Replaced the hose clamps. Considering solder soon...
This is the setup above the wand:
My release valve.  The ball valve opens to atmosphere.
My release valve. The ball valve opens to atmosphere.
On the left the pipe comes from the boiler, on the right I usually have a cork in the "L" offshoot for "pressure monitoring". The valve is for release at the end of the mash. I remove the wand as soon as the mash is over, take it apart and clean it so I decrease my risk for clogging on later runs.

The mash tun is always open so I don't worry about the pressure in there. The back pressure is the only pressure I worry about.

Now... I NEVER leave anything that is running. This goes for steam mashing or distilling. I work in my basement and I like the house just the way it is.... I have no desire for a remodel following a boiler rocket through the floors and roof of my home.

All of this being said, and since I am constantly, persistently, neurotically watching the setup work... I like the idea of a better monitoring system and not a safety system. Ergo.... I manometer of some sort.

Shady, I knew you were going to suggest your manometer/water trap. I've seen you recommend it at least a dozen times and I like the idea. I have seen the water trap pic you have and I think I caught how you connect it to the boiler (small pic and I thought I saw it in the background...maybe not). Both you and rad make the suggestion that it's probably better to know when your headed into trouble instead of already there and I agree! However, instead of a 6 foot manometer... I would rather a gauge. Similar to the one from the acetylene torch you used in one of your setups. Maybe something like this:
gauge.jpg
I would place it in the L where the cork now resides. If I understand the physics then the pressure above the tun (back pressure as well as forward pressure from the steamer) should be equivalent in the L section and mounting a gauge there should have the desired effect.
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shadylane
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Re: PRV

Post by shadylane »

The pressure gage on my rig is pretty much worthless, :oops:
By the time the pressure has built up, enough to even move the pointer on the gage
The boiler would be over pressured and dangerous. :shock:
Using a manometer, I can easily see a change in pressure as low as .025 psi
One other thought,
Using a cork for a PRV is better than nothing, don't take the cork out and put a useless analog gage in it's place.
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Re: PRV

Post by Blarney Stoned »

RG, Google Dwyer certified low pressure gauges. They'll pick up a mouse fart.
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Re: PRV

Post by shadylane »

:thumbup: on the Dwyer certified low pressure gauges
The gage will need to be installed correctly.
you will need something like this :lol:

http://pointing.spiraxsarco.com/images/ ... 12_6_2.gif" onclick="window.open(this.href);return false;" rel="nofollow
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Re: PRV

Post by Blarney Stoned »

EZ. Works like a water hammer but keeps the funk away from the gauge. :thumbup:
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Re: PRV

Post by shadylane »

And looks just like a manometer :lol:
Long story short, want to use an analog gage instead of a manometer.
You'll need a trap to protect the gage. :lol:
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Re: PRV

Post by Blarney Stoned »

shadylane wrote:You'll need a trap to protect the gage. :lol:
EZ.Come off the boiler to a Tee. Gauge up,trap down with a drain valve on the bottom of the trap.. Maybe someone can do a little sketch.
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Re: PRV

Post by Brutal »

I also plan to install a gauge. I actually bought mine already (over a year ago) but haven't installed it. I believe mine has a compression fitting for a small diameter tube. I was going to get a roll of tiny copper tube and run it upward in a spiral to the gauge. That way pooling couldn't affect the reading and the gauge would not be exposed to steam. It would all condense on the way up the copper spiral.
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