Can I run 1″ stain steel gas line that will have 60 psi on the top edge of 24″ alum. cable tray?
A few concerns:
Depends on the tray layout, but somebody might want to clamp a roller on the side of the tray in the future to pull in another cable. Sure, they can put the roller on the other side, but with pulling tension, sidewall pressure, and bending radius it can be important to have the roller on one particular side.
Even though it isn't supposed to happen, sometimes electricians are inclined to walk or crawl on the tray set up a pull, tie wrap the cable down, etc. Having a gas line mounted on the rail of the tray would be a safety issue, and even thought people aren't supposed to walk the tray we have to plan for the reality of working in a plant.
We don't allow cable tray to support other "stuff" in the refinery where I work. In many cases people will attach some new steel to the structural supports for the cable tray to support pipe rather than using the tray itself.