Need help finding a gas needle valve for natural gas fired oven...

[Satan]

As the title states, I need help locating a gas needle valve for a natural gas fired oven. History... I built an oven for a friend of mine and when it was built my friend could not source a needle valve where we live, Colombia, South America, so his gas line installer installed a 'ball' type valve. It works to the extent that you can open and close the flow of gas but it doesn't allow for precise control of the flame. That being the case his chef is having problems maintaining precise control of the flame which makes it extremely difficult to maintain the correct temperature inside the oven. I have searched for hours and hours for a gas needle valve for a low pressure natural gas application but it appears there in no such beast. I found tons of high pressure gas needle valves but nothing specifically for a low pressure natural gas application. Does this type of valve exist? My knowledge in this area is nonexistent so any help would be greatly appreciated. One last thing... My friends gas line installer has requested a 1/2" NPT female x 1/2" NPT female valve.

Thanks in advance for any help or suggestions provided.

For those curious here is a link to an online photo album of the build for the oven I built here in Colombia:


http://s268.photobucket.com/user/M_P...?sort=2&page=1

[pounce]

What brand and model burner is that? Looks like its got a solenoid ahead of a valve. Best to pull the manual and see what is requires first.

[Satan]

Thanks for your reply.

The burner is a one off unit built by a local technician who specializes in high output burners for kilns etc. We asked him for a needle valve to install with his burner but he says they're not available. Personally I thought he was just being lazy and didn't want to search for one. The valve needed is located before the burner and not after the solenoid. It appears in the photo that there is in fact another valve located after the solenoid but that's not the one we're trying to replace. The valve in question is basically an on/off gate or ball valve which provides no precision control of the flame and it's located several feet before the actual burner unit.

[UtahBeehiver]

Any natural gas or propane supply house will have needle valves. Even Ebay carry needle valves. For natural gas or propane, carbon steel, stainless steel or brass will work. Galvanize and natural gas are not compatible. I was from the natural gas business and we used Swagelok or AGCO valves all the time.

[pounce]

so his gas line installer installed a 'ball' type valve. It works to the extent that you can open and close the flow of gas but it doesn't allow for precise control of the flame. That being the case his chef is having problems maintaining precise control of the flame which makes it extremely difficult to maintain the correct temperature inside the oven.

The valve in question is basically an on/off gate or ball valve which provides no precision control of the flame and it's located several feet before the actual burner unit.

I get that you are asking for simply a link to a needle type valve you can find to deliver to you in your country, at the same time I'm confused about your statements and wonder if there is some additional help to be offered.

Are you wanting to control the flow/pressure of the natural gas to the unit because it it flowing too much gas or the flame is too large? Or what exactly is the chef looking for when they want precision control?

BTW: nice looking install. I like the approach with the sand and newspaper. Clever.

From the images it looks like it would be sort of difficult for a person to get up under the oven to operate the burner controls. The control box is pretty close to the actual burner so if its mounted in the floor its upside down and just below the floor. Is that why the chef is wanting to control the gas pressure from a valve far behind the burner? Sounds like you want a regulator and not a valve.

[Satan]

Any natural gas or propane supply house will have needle valves. Even Ebay carry needle valves. For natural gas or propane, carbon steel, stainless steel or brass will work. Galvanize and natural gas are not compatible. I was from the natural gas business and we used Swagelok or AGCO valves all the time.

If my ignorance in this area isn't obvious it will be when I ask if there is a difference between a propane gas needle valve and one for natural gas? If there is no difference then I have solved the problem, which if I wasn't clear in my first post, I want to find a "low pressure" gas needle valve for a natural gas burner. Also, if a "high pressure (6000 psi) gas needle valve can be used in a low pressure natural gas application then again, I have solved the problem.

[Satan]

"Are you wanting to control the flow/pressure of the natural gas to the unit because it it flowing too much gas or the flame is too large?"


Yes, the chef wants to control the gas flow which adjust the size of the flame which in turn will adjust (raise or lower) the temperature.

"From the images it looks like it would be sort of difficult for a person to get up under the oven to operate the burner controls. The control box is pretty close to the actual burner so if its mounted in the floor its upside down and just below the floor. Is that why the chef is wanting to control the gas pressure from a valve far behind the burner? Sounds like you want a regulator and not a valve."

In addition to all the gizmos attached to the burner that is mounted under the oven there is a remote box (located in front of the oven where the chef has easy access) that has a switch that turns on and off the burner. There is also a gate/ball valve right next to the remote on/off box that the chef uses to adjust the flame. There is no need to get under the oven to adjust or turn anything on or off.

"Is that why the chef is wanting to control the gas pressure from a valve far behind the burner?"

The valve that the chef uses to control the flame is located before the burner and not after. The valve you saw in the photo (the valve with the red handle) is never touched by anyone with the exception of possibly the technician who installed and set up the burner.

Sorry for my lack of expertise and understanding of this subject. This is all new territory for me.

*Thanks for the kudos on the build. It was my fourth oven. I'm now starting my fifth which will be for a mobile application. This time I'm using castable refractory concrete. I'm also fabricating a stainless steel igloo entry much the same as FB uses on their FB TE 120. Mine won't be that big, this one will be my smallest oven to date at only 100 cm.

[Satan]

I just found this at Grainger:

https://www.grainger.com/product/GRAINGER-APPROVED-Needle-Valve-Inlet-Port-1-5TUL1?s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/5TUL1_AS01?$smthumb$

Will this work?

[UtahBeehiver]

You need a pressure rating on the needle valve to be at least 1.5 times the maximum inlet pressure you will see in the inlet of the valve. Needle valve have tighter flow control of flow than ball or globe valves. You also need to make sure the needle valve has the capacity to meet the maximum flow the your burner requires plus a contingency. The flow requirements should be listed on the burner unit. A ball or globe valve typically have more flow capacity than a needle valve (also know as a Cg factor, high Cg more flow capacity). So there are several factors you need to look at.