Joseph R Tornado , WV January 02, 2016 Appliance: Tappan Gas Range TGF336AUE Tappan Range Tgf336aue: Tappan gas oven slow heating. How to replace Tube To Valve (3/8" Tube). After finding a model number on the range, I used the online parts diagram you provided to locate the part and part number. Ordering was super easy and the replacement was only two threaded fitting. It only took a couple minutes. 1 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes