H1B visa transfer with i140 Approved while in India

[SRan]

Hi,
I have an approved i140 from Employer A and here in USA on my H1B with Employer A. My H1B visa will be expiring on Sept-2019. I am planning to go back to India on May/June 2019 and stay there for an year due to personal commitments.

Questions:
1. While in India, Can I join Employer B for similar type of work & have my visa transfer done based on Employer A's i140?
2. Do I need a copy of the approved i140 from Employer A for future visa changes?
3. Can employer B do a visa transfer after my current visa expires on Sept 2019? 

TIA

[adshah84]

1. Yes

2. It will be good if you have copy of I140. Original don't needed. 

3. Yes

Assuming it's been 180 days since your I140 approved