I know this has been hashed around a good bit, but usually I see 1 out of 20 furnaces that I inspect being Propane/Gas fueled. This line and sediment trap was the first I have seen. I have always seen the shut off valve located on the vertical pipe upstream of the elbow with the trap being located at the bottom of a vertical run, with a horizontal tee located directly above and leading to the unit.
My guess is this configuration is improperly installed?
I suppose it does. I’m no HVAC tech but if the home had multiple appliances being served by the gas line, I would install the drip leg as soon as possible after entry into the home. But if only the furnace is being served, the location is probably ok. But it is still not a sediment trap!
Virtually nothing is/was required in my area when this system was put in. It’s not in violation of anything or has to be noted as in need of correction or not. I was more interested for leaning reasons, which is still not absolute, but based on my area, it seems trivial enough to pass on and let the next inspector bring it up.