I am an Indian citizen an would be touching Bangkok airport just for 50 mins and then catch the flight to Calcutta,India. Is there a need of any transit visa?

I had lost my passport at USA but now have a valid one issued by Indian consulate, San Fransisco. Is my passport sufficient for safe travel?

You do not require any visa for Thailand if you stay will be less than 12 hours, you have onward documents and do not leave transit area.

Your passport is ok for entry into India if you are only an Indian citizen.

You do not require any visa for Thailand if you stay will be less than 12 hours, you have onward documents and do not leave transit area.

Your passport is ok for entry into India if you are only an Indian citizen.

I was in the Thai Consulate in Kuala Lumpur on Tuesday.

At the next window a guy travelling on an Algerian passport was trying to get a visa for Thailand (Tourist). He was told he could only get one in Paris or Nice.

He eventually wound up with a <12-hour transit visa, which would allow him to catch an Emirates plane back to France. Might be different for other nationalities, but this was a 'maximum 12-hour' transit visa.

(And don't even think of leaving the airport )

He eventually wound up with a <12-hour transit visa, which would allow him to catch an Emirates plane back to France

My quoted post is correct AFAIK. He should not require any visa for Thailand.

A "transit visa" is valid for 30 days travel inside Thailand and then onward connection to another country. Source: MFA Visa Web Page

If its only a 50 min stopover to change flights why would he need to clear immigration anyway? For transiting passengers to onward flights that need to change terminals, there is ground staff that escort passengers to the other terminal, you never go near immigration so you don't need any type of visa. The transit visa is designed for people who will need to spend extended time between flights. I used to travel from Australia to Vietnam and the flights don't meet up so there is a 9 hour stop over which Thai airways give you a free room at the Amari to make it more comfortable. For this you need to clear immigration and then depending on what visa you have as to whether you pay for departure tax or not when you leave.