Ward Burner Systems

Orifice Charts

We've taken, what for many, was guess work and made it as simple as 1-2-3. By using our charts for Natural Gas and Propane (LP), you can quickly and easily determine the BTU output of your burners, know what size orifice to drill, and know the effects of altitude.
Charts are printed in two colors on heavy card stock, then laminated with 5mil plastic on both sides, and edge sealed. Made to take abuse and last. To determine BTU's per Hour: Multiply Pressure Function by Orifice Function. To determine Orifice Size: Divide known or desired BTU's/Hr by Pressure Function, then match up your Orifice Size. Altitude effects are determined by multiplying your answers by the Altitude Function. Please specify either Natural Gas or Propane.
These Charts Provide:

49 Different Pressures • from 4"wc to 25 psi
Altitude Adjustments • from Sea Level to 11,000 ft.
137 Different Orifice Sizes in Fractions, Numbered, and Lettered • from #80 to 1/2"
Over 73,000 Different Combinations

So, you just dropped your Venturi Burner right on the brass part sticking outa' the back of the burner....it's busted, now what? We carry replacement orifice spuds (also called mixer pins), for the burners we sell. Or use these, along with our orifice chart, to build your own burners. Price includes sizing and orifice drilling.

Orifice Plugs

We carry four different orifice plugs. Type A: fits Ransome B-3 thru B-5, 7/16" x 27. Type B: fits Ransome Pilot burners, 1/4" x 28. Type C: fits MR750 & MR100 burners, 11/32 x 32. Type D: fits our MB series burners, 1/4”npt.

Undrilled Price: $5.00

Drilled Price: $7.50