Back in my days of erector engineer (and I'm talking of the early seventies) I've used E 7010 for the first pass and E 7018 for the subsequents.
5P is a Lincoln brand of electrodes. We used another brand (Philips, if I remeber well)
Giovanni S. Crisi
Sao Paulo - Brazil
Depending on the pipe and what you are testing for you may run the bead with 5p+, 70+, or HYP. Hot pass can be 5P+, 70+ or HYP. There is no "common" rod used. A lot of companies use 5P+ and 70+ for just about everything while others don't. You just have to ask the welding boss where you are testing what is to be used for that company on that day.