Flange Union

LionA29

What is the best Flange Union to use on Drop Header? Looking for one that doesn't use gasket. In the attached pic, does that use a gasket?
Any input is appreciated, thank you.

Paul48

There's flanges, then there's unions. Flanges use gaskets, unions rely on a ground joint that forms the seal. You picture shows flanges.

LionA29

In the pics, those flange used gasket?
Thanks

Paul48

Those are pipe flanges, and they use gaskets.

nicholas bonham-carter

JStar here recommends using unions, or flange joints only on the vertical pipes, to avoid possible leaks. As well as that, a union placed above the boiler on the riser, will make it easier in many years to replace the boiler.--NBC

EzzyT

I use regular unions, flanged companion unions and cast iron flanged unions they all work great. Just like @Paul48 mentioned the flanged unions use high temp gaskets and they work perfectly fine