PROCESS PIPING DRAFTING By Rip Weaver: A very nice book in simple easy to understand language.
PIPING DESIGN HANDBOOK by John Mcketta: One of the good books.
THE PLANNING GUIDE TO PIPING DESIGN by Richard Beale and
THE FUNDAMENTALS OF PIPING DESIGN by Peter Smit

The above listed books is very useful for Piping Engineer if anyone is having Please share.