L1-B individual visa stamping for extension petition.

[venkatapaidmarri]

L1-B individual Visa:
What is the difference between Visa expiriy and PED date on L1B visa and how does it effect re-entry to U.S.
For example I am currently with L1B individual status in U.S.:
                Visa Expiration Date: 14 SEP 2021
                PED: 19 JAN 2019
                Extension petition has been filed which was approved with validity till 19 Jan 2021. (note that there is client and loacation change in extension petition)
 
                In case I travel out of the country (U.S.) do I need to go for visa stamping? 
                from the various forums gone through, my understanding is, can re-enter the U.S. by presenting the below (without going for a new visa stamp):
                    1) Existing visa with the expiration date of 14 SEP 2021 (and PED on visa stamp as 19 JAN 2019)
                    2) the new I-797 authorizing L-1B status until 19 Jan 2021.

Any suggestions are appreciated...