 On the Road Again  is a song made famous by country music singer Willie Nelson.n the Road Again became Nelson's 9th Country & Western No. 1 hit overall (6th as a solo recording act) in November 1980, and became one of Nelson's most recognizable tunes.
The most common types of rigid ductwork are: 1  Sheet metal ducts. These are the kinds of ducts youâve seen in films â usually with an action hero crawling through them! 2  Fiberglass lined ducts. These are sheet metal ducts (like those described above) that have internal or external fiberglass lining. 3  Fiberboard ducts.
Pipe threads are either tapered or straight (parallel). The two styles may or may not be compatible. Refer to thread information. chart on page 706. Tapered threads. Tapered threads are the most common type of thread available. As the name implies, they. have a slight taper. When mated together and tightened, the threads compress and may form a. seal. Usually a thread sealant is required. The mating threads both hold the fitting in place and. seal the connection.