Solenoid Valve Pressure Drop Issue with Natural Gas

[OBBrewery]

I am building a single tier system similar to Brutus 10. Natural gas system, three 8" jet burners, two of which have gas flow controlled by STC 2W160-3/8 solenoid valves.

I hooked up to natural gas and lit the boil kettle burner (no solenoid valve). Works great!

I fired the other two burners with the solenoid valves and it seems they don't allow enough gas flow through them to get a decent or hot flame.

Is there something I didn't do correctly when sizing my manifold or valves to account for a gas pressure drop?

The Cv value of the solenoid valves is 4.8, I don't really know what this means.

My manifold is set up with 3/4" main manifold beam with pipes reduced to 3/8" for solenoid valves and burners. The manifold is just black gas pipe bolted onto the frame of my rig.

Help! Thanks.

 

[BrunDog]

I don't do any work with natural gas, but a Cv of 4.8 is pretty big for pressure systems. Natural gas regulators run at 0.5 psi (I think). Can you increase the pressure of the regulator or swap it for a higher value regulator (~2 psi)?

 

[OBBrewery]

Thanks BrunDog. There is no regulator except the one on the gas meter. I have my gas line tapped directly off of the house side of the meter so the pressure is whatever my gas meter gives me.

 

[jddevinn]

What burner do you have? Many burners are made for high pressure gas.

 

[OBBrewery]

This is the 10 jet burner: http://www.bayouclassicdepot.com/products/10-jet-natural-gas-jet-burner-618ng

 

[OBBrewery]

Anyone else have any ideas?

 

[BrunDog]

Is the valve rated for gas?

 

[The_Bishop]

How are you getting the gas to the rig?

Pictures of the setup would help troubleshoot.

 

[BrunDog]

I suspect this is not a valve made for this application. Which is possibly unsafe - I would get one of the Asco valves or likewise intended to switch gas.

 

[OBBrewery]

View attachment ImageUploadedByHome Brew1477832599.558997.jpg
Overall setup

View attachment ImageUploadedByHome Brew1477832650.447187.jpg
Gas manifold

View attachment ImageUploadedByHome Brew1477832674.710793.jpg
Closeup of gas manifold at HLT

View attachment ImageUploadedByHome Brew1477832709.424385.jpg
Burner assembly from below

View attachment ImageUploadedByHome Brew1477832751.866922.jpg
Burner from above

Link to STC valve product info:
https://www.stcvalve.com/Product-Literature/2W160-500.pdf

I will only use my system outdoors. I have a 3/4" gas line tapped just after the meter, installed specifically for brewing. Main manifold is 3/4", reduced to 3/8" before the STC valves. I have copper tubing for the pilot light, terminated with a single orifice tip for natural gas in the middle of the two controlled burners. Pilot lights are only controlled by a manual gas valve for simplicity. They will stay lit for entire brew day, similar to Brutus 10.

 

[OBBrewery]

Just realized the STC valves are for inert gas. Natural gas is not an inert gas, so I do probably have the wrong valve for this application. Has anyone out there used an ASCO valve for natural gas? If so, which model? Or pointers on how I figure out which to use? Thanks!

 

[jrcrilly]

Running gas without a feedback system to kill the flow if the pilot or burner goes out seems very risky to me. That is why I used Honeywell solenoids with safety features built in. I would suggest looking into those. I use only a 1/2" manifold and can run three low pressure burners at once with no apparent pressure loss.

 

[The_Bishop]

Those burners are 100k btu each. 3/4 pipe at 10 foot length is only rated for 230k btu, so that could be part of the problem. What size is the hose that connects your brew rig to the gas supply? If you're using one of those stainless flex lines for appliances, that's a good bet for a choke point, at well.

 

[jcav]

It says operating pressure of that valve is 100 psi, and natural gas is like .5 psi or 10 inches of water column if I remember correctly. Use the Honeywell valves with natural gas. Might need more info on that burner to see if that will work with natural gas also.

John

 

[OBBrewery]

Thanks guys. Burners were listed at 70k but, so I should be fine with 3/4" pipe. I have a 4' length of 3/4" flex gas line (similar to what you would use for your stove or dryer). The rest is 1" gas line reduced to 3/4". I hook it up about 8 feet away from my gas meter. The boil kettle burner doesn't have a solenoid valve and it was running great, so I know I'm getting enough gas into the manifold.

Looks like I need to look into the Honeywell valves. I'm just a little reluctant to because I've already put so much money into the rig and the Honeywell will probably mean I need to rebuild most of the manifold.

 

[jcav]

I know it's a pain, but you've come so far already and your doing an awesome job. Once you get it done the right way it will be worth it. You will be happy and it will be safe and fun to brew on. It just adds up quickly this obsession we have .

John