I have seen it in application many times, just not in this application of course. But I thought I had read of cracking issues with some of these pipes. You need other factors such as tensile stress for IGSCC to occur you wouldnt have significant tensile in this application but you could have some as a residule stress from the welding operation. Like I said I dont know how much of a factor it might be but the L grade just seems like it would be cheap insurance.