Difference in Valves?

[steve_81]

What are the main differences between the X valve and the RT valve?

[michbich]

X is made of aluminium
RT is made of stainless steel

That's the biggest difference.

Another difference would be the acceptance of the ULT. Most RT's don't, some can be modified.

[Engus]

are you asking about the classic RT or the RT pro?

[questionful]

"RT valve" generally refers to any valve that functions like this:

http://www.zdspb.com/media/tech/animations/rtemag2_6fps.gif

Do you mean classic RT?

X is made of aluminium
RT is made of stainless steel

That's the biggest difference.

Another difference would be the acceptance of the ULT. Most RT's don't, some can be modified.

That's not the biggest difference. The biggest difference is that classic RT valves aren't compatible with anything but a classic RT body and rail. And they're air-thru fieldstrip screw. And the regulator housing is aluminum like in ReTro valves.