I've purchased a pilot burner (part # LH 680 005) for a Carrier 58GS150-CB furnace. The installation looks simple enough except for the gas supply tube for the pilot. On the pilot burner there is a threaded brass fitting with a taper that fits into a taper on the orfice. How much do I tighten this brass nut? Can I reuse the existing tube from the gas valve? It doesn't look like the old one used any pipe dope but I haven't removed it yet. Any info would be greatly appreciated. Thank you. If it's of any help to others with a similar problem, the pilot burner on my furnace causes the gas valve to chatter for a moment when pilot burner is warm and calls for gas. Once the gas valve is open is remains so until the furnace cycles again. I can also see the ignitor occasionally fire with the burners on. When the furnace is cold or a long duration between cycles the gas valve doesn't chatter.