Adding a pattern to a pipe like G for gas pipe.

[isosa9APBT]

I'm creating a multi-discipline layout and I was wondering if I can add a initials of letter to the pipe itself. Without labels it's hard to know what each pipe is. I seen in civil how they have legends for their pipes and they will have initials or letters with in the line to tell each utility apart. Is there a way to do the same for mechanical in Revit? i attached an image of what i would like the pipes to look like based on a civil plan.

[SteveKStafford]

Revit doesn't permit adding text to line patterns. The intended approach is use pipe tags that identify their System Abbreviation parameter. This way you can place tags on a pipe or several along a pipe to do the same thing.

Relying on a line pattern can problematic when sections of pipe are very short, there isn't enough length for a patter to develop. The tag approach is a different task but can be done pretty quickly with the Tag All (untagged) tool.

[L.Maas]

Why not use colours and hatches to differentiate? Now that Revit 2019 allows for and background patterns there should be enough to differentiate. This in combination with some tags, as proposed by @SteveKStafford, should be sufficient to  separate the different systems.

With some well thought out hatches they probably could even hold up in black and white print outs.

[AzWoodWarrior]

I would love to be able to use colors to differentiate hot, cold, nat. gas, but unfortunately the municipalities i deal with only accept grayscale so I have to settle for line patterns and weight. I haven't been able to get a hatch to show on an object as thin as a pipe. Do you have any suggestions for me?