Though your pressure is very low, the temperature is not, and, depending on the application, there are other issues to be considered (sustained loads, long term behaviour, regulations...): you should definitely consult a professional engineer.
Generally speaking 304L is not the best for that temperature: plain 304 is better. prex
motori@xcalcsREMOVE.com
According to the ASME code 304L is not suitable for temperatures above 800F. You need 304H to go to the full temperature of 1400F. This is presumably because of the risk of creep, 304H having better creep performance than 304L due to its higher carbon content. And the advantages of using 304L, resistance to sensitisation, does not exist at high temperature, as sensitisation is inevitable. What about corrosion, stainless steel may suffer severe corrosion in certain environments?
What about 310S? We just worked with that material on a piece of natural gas-fired equipment. It's got 0.08 carbon content, it works great above 2000 deg F, with no chromium carbonate precip (sensitisation). And it's fantastic for wild temperature cycling (heat-ups less than 2 minutes, etc).
I second Prex, INBCPE, and Welding1. It is best to look at specific codes and standards that apply to the application. These codes are for the purpose of giving the designer and fabricators safe application standards and fabrication standards based upon past experience. If the application is flue gas corrosion products can be substantial and 304 may not be fit for purpose.
