https://www.asme.org/learning-development/learning-experiences/piping-and-pipeline-engineering-program

https://www.findamasters.com/masters-degrees/?Keywords=pipeline+engineering

https://www.educations.com/institutions/the-international-institute-of-plant-engineering-and-design/master-in-piping-engineering-and-design

So it has a different name than "masters of plumbing". So what? Literally what is your point?