Normally you have to close the pipe just to clear and release resources. Let's say, you open 1,000 times the same file for read only, that's a lot of resources to allocate and might require memory and make your programs sluggish. However, as long as for data consistency, no problems should arise.
Do notice that if you attempt to write on the file, you'd have issues as for data consistency, because you can not longer rely on the order that the processes are operating.
I hope this helps