Exclusive, patented design of refractory plug “E” and combustion tunnel ensures smooth stable operation. The long annular orifice “F” reduces back firing even at very low mixture pressures.

Turbulence created by the nose plug and the stepped burner block “G” provides positive flame retention at high mixture pressures with shorter flame length and higher heat release (on std. block only).

Pyronics Tunnel Burners are easily lighted at stated mixture pressure. The pilot tip “H” is screwed into the body to ensure permanent and correct location of the pilot flame. A second threaded hole is provided for accurate location of flame electrodes at the junction of the pilot and main flame.