Both Sturgisafe and Camco make several "Tees" for installation in a hard piped gas system. The will connect to the TANK before or after the regulator depending on which you prefer. If you are using cylinders as most trailers do, they make the same "Tees" for cylinders.
Extend-a-stay was purchased by Sturgisafe and they make the same propane fittings. If your ordering on line call the store first and tell them what you need or look at their on-line catalog if they have one. If buying from a S&B store ask for recommendations, same with a Propane outlet.
If you are not familiar with pipe sizes and fittings definitely get professional help.
Contrary to popular belief, not all RVs have hoses in their systems and therefore, are more difficult to work on.
If you need to go to a store, take some pictures so the sales staff knows what you have.
Easy job and not real expensive but be safe and don't skimp on whatever you use for joint sealant and then test thoroughly for leaks.
Chuckbear, Camco, Sturgisafe and MEC all sell the brass fitting without the hose, it is just that not all suppliers carry them in stock or advertise them. if you go to a Propane shop, in my opinion the best place to go, they will sell you what you need. You do, however, need to know what you need or take pictures or your RV to them so they really know what you need.
"I travel not to go anywhere, but to go. I travel for travel's sake. The great affair is to go". R. L. Stevenson
David Bishop
2002 Winnebago Adventurer 32V
2009 GMC Canyon
Roadmaster 5000
BrakeBuddy Classic II