So now that I finally feel like I know how to use my roaster, I've decide to complicate my situation again by converting it to use natural gas.

I'm using a Santoker 500 and had the unintended opportunity to learn about enlarging the orifice myself, so I think I have that part covered.

My question is regarding the flow gauge on the front of the roaster. If I were to enlarge the orifices, the pressure displayed on the gauge should go down, correct? Because I'm putting more gas through at a lower pressure? (all other things being equal).

Basically I'm trying to figure out if I'm going to need to replace the gauge as part of this conversion, or if not, understand how the display on the gauge will change post-conversion.

Thanks in advance!

frank

Residential natural gas pressure is typically about 3.5" of water column vs 11" for propane. Propane has a higher energy content also. That's why you'll drill out your orifice(s).

I'm going to post this for posterity:

Here's a couple of handy links:

http://millcityroasters.com/wp-content/ ... -Chart.pdf

http://millcityroasters.com/wp-content/ ... -drill.pdf

Find the size of your current orifice by using the shank end of a drill bit. Orifices are drilled out in numbered wire sizes. For instance, under the LP column, a #70 is about 5500 BTU per hour. The same BTU for natural gas is about a #56.

Then drill out your orifice(s) like this:

[youtube]https://www.youtube.com/watch?v=-OZ2CUi-Qvk[/youtube]

For anyone attempting this on a system with a pilot light, remember that the pilot has an orifice too, but you probably can't drill that out. You'll need the replacement part.

Frank, your gauge will read about 1 kpa. If you have enough graduations, you might be able to use the same gauge. If not, you'll be better off with a 0-5" water column gauge.

Thanks Steve!