What are these?
#1
Member
Thread Starter
Join Date: Mar 2009
Location: United States
Posts: 459
Upvotes: 0
Received 0 Upvotes
on
0 Posts
What are these?
My guess is they are check valves but I'm not sure. This is on my .75" propane line.
#3
As gilmorrie said, they are unions. When using threaded pipe, you can't join two different runs together because of the threads. This allows you to make that connection. It also allows an easy point to disconnect the piping.
#5
That second pic is a 'coupler' and only joins two lengths of pipe. Both ends are threaded.
The 'union' in your first pic (aka 'ground joint union') can be separated by loosening that locknut.
This pic shows one taken apart:
image courtesy weiku.com
The 'union' in your first pic (aka 'ground joint union') can be separated by loosening that locknut.
This pic shows one taken apart:
image courtesy weiku.com
#6
With a coupling at least one of the pipes need to be able to turn freely, that is not screwed into something else. A union can be used when neither pipe can be turned freely, that is both pipes are screwed into something else.
#8
Member
Best to browse the pipe-fitting department of a good hardware store. You will find - all sorted and labeled - tees, crosses, caps, plugs, nipples, street els, regular els, ball valves, boiler drain valves, gate valves, globe valves, hose bibs, and more. Their individual purposes are often obvious by inspection.