Gas valve for high temp salt pot

[efleming]

I'm in the process of building a high temp salt pot. I understand all the components necessary to assemble and have done a fair amount of research on this topic. Some of the link's in the Sticky section have been of great help.

The one area that seems to be a little slim on information is the selection of a proper gas valve. I'm leaning towards a Honeywell VR8345M4302 Universal Electronic Ignition Gas Valve --> http://www.drillspot.com/products/4...M4302_Universal_Electronic_Ignition_Gas_Valve

I'm looking at a valve that will handle both NG and LP as I would like to experment with both.

My first simple question is, will this work for the gas control valve?

Some more detailed questions are as follows:

What BTU level is necessary for this application?

Is 3/4" Inlet and 3/4" outlet sufficent?

Some valves state a maximum gas pressure and some do not. Can one assume if a max pressure is not listed that the valve will handle the appropriate pressures of a propane burner (~6-10psi)?

What are other key items to look at that I may not be listing?

I know I've got a lot of questions here but I think answers to these questions will help others in the future.

I'm hoping that some of our experts with current salt pot operations will chime in here. Thanks!

 

[efleming]

Here is a similar layout of gas controls I am planning on setting up once the proper gas valve is selected.

Any expert advice here?

 

[efleming]

Wow... 60 views with no replies... Is this a topic that I am trying to over think? I'm very aware of the respect one must give to a high temp salt pot. I've seen many good threads such as --> http://www.bladeforums.com/forums/showthread.php?s=&postid=2485597 and build guides as well.

Don Fogg's site is the only one that mentions a specific gas valve but he also mentions he runs a 1/2 lb regulator with it. I could not imagine my current forge getting up to proper temp with just 1/2 lb of pressure.

I'd really like to understand this one mysterious item "gas valve" from someone who has done it rather than making trial and error purchases of $60-$100 valves.

Could a current gas salt pot owner chime in with some experiences? Kevin, Nick, Bruce?

Replies to this topic are spooky quiet...

 

[Lane]

First let me say I havn't made a high temp salt pot, but have acquired everything I need. From the research I have done some are using a solenoid valve 110 volt that operates at a higher input and output pressure, I have seen some valves that operate at up to 15 psi.

The typical combination valve simular to the one you showed has an input and output of less than 1 psi and closer to .5

Then there are the many safety hazards that come into play when using a burner that shuts on and off via a digital controller. Much less the fear of a killer volcanno waiting to go off.

I'm looking for a good pilot circuit design with electronic ignition and safety's. I'm pretty sure I can design one, but would rather get the info from someone that already did.

I'm still in research mode, or scared.



Lonny Ritter


The natural gas at my house is around 7.78 inches of water column or 4.5 ounces. I have heard of others making a forge work with natural gas, at 4.5 ounces of pressure I don't know. Im going to stick with propane until I live somewhere that offers higher pressure.

27.7 inches of water column = 1psi

1 cfh of natural gas = roughly 1000 btu
1 cfh of propane = roughly 2000 btu +

 

[Stacy E. Apelt - Bladesmith]

That looks like the setup I posted a diagram of a while back.Nice job.Looks like you have it set up to run two different salt pots at one time.
I am not sure what you want the valve to do?
The double control you show has two valves, each controlling the High and Low cycles of a burner. Since the flame never goes out, there is no concern (as Lane was stating) of the great WOOOFFF when the unit reignites, as with single stage controllers.
What you show is all you need. I have never given much thought to the solenoid valves, as far as LP vs NG. They are just turning the high stage on and off. I think the expensive controller valve you listed would be for a much larger system, and has features you don't need. The two stage (Hi/Lo) system takes care of ignition (once you light it ,it stays lit) and the PID takes care of cycling the HI stage on and off. All you need is a valve that can pass as much gas as you need (1/4") and can take 5-10 pounds of pressure ( unlikely you will be running a salt pot with anything near that much gas flow).
Stacy

 

[efleming]

Hello Lonny and Stacy

Thanks for the replies.

Lonny,

Then there are the many safety hazards that come into play when using a burner that shuts on and off via a digital controller.

Take a look at the gas control pannel in the picutre above. It completely eliminates the burner ever going off. This is not my setup as I have not purchased my gas valves yet. This is IMHO one of the better examples of gas management that I've seen in all my research. By using the needle valve with one line always open (bypass gas valve) you set this gas flow very low. When the digital controller shuts off the gas valve that provides higher flow, the bypass gas line keeps the burner running at a low rate, not high enough to produce increased heat but enough to keep it from going out. This setup eliminates the need for spark ignition.

Stacy,

That looks like the setup I posted a diagram of a while back.Nice job.Looks like you have it set up to run two different salt pots at one time.

This picture is not my picutre but, one i found a number of months ago while doing research. The site I got it from is no longer up so i'm glad I saved the picture. There are many dead links when trying to research this topic...

I do plan on using a similar setup to this picture as I really like the fact that the burner never goes out thus eleminating the need for spark ignition.

You are correct that this setup came from someone running both a high temp and low temp salt pot configureation.

All you need is a valve that can pass as much gas as you need (1/4") and can take 5-10 pounds of pressure ( unlikely you will be running a salt pot with anything near that much gas flow).

This is my delima. The less expensive valves ($50-$60) all seem to have a 1/2 lb pressure max. As I get closer to $100 valves with larger 3/4" inlets, the maximum pressure rating is not present in the descriptions. The $64,000 question is "Will a gas valve rated at 1/2 lb pressure handle the 5-7lbs pressure needed to operate a salt pot burner? or Do I need to spend the extra $$ and get a much higher volume valve, such as the one I posted above, to do the job?"

Any manufacture names with part numbers of gas valves that have worked for other people would be greatly appreciated. Thanks for your feedback! :thumbup:

 

[Stacy E. Apelt - Bladesmith]

I'm pretty sure that is one of my systems. I designed it to run two salt pots, or to use one leg only to run a controlled forge.
Anyway, Here is a possible sources for the valves at lower prices. I buy all mine off Ebay.

http://cgi.ebay.com/3-8-Gas-Solenoi...VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247
This source has eight of these and many others available.


Now, if you are an experimenter/inventor here is a bonanza. About $10,000.00 ( maybe much more) of your tax dollars for $200:
http://cgi.ebay.com/Lam-Research-Ga...ryZ58295QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Wish I was in Texas.I'd love to take a look at this box.
Stacy

 

[efleming]

I'm pretty sure that is one of my systems. I designed it to run two salt pots, or to use one leg only to run a controlled forge.

Well great design Stacy. I really like it. Thank you for your great information. The valve from e-bay looks like it will do the trick and for a much better price than what I was looking at.

Now, if you are an experimenter/inventor here is a bonanza. About $10,000.00 ( maybe much more) of your tax dollars for $200:
http://cgi.ebay.com/Lam-Research-Gas...QQcmdZViewItem

Man, who fun it would be to play with that! Not a bad price too...

Again, thanks for your info Stacy!