I observed a TPR valve that did not have a discharge drop pipe attached to it’s outlet. This is a hazardous condition as the occupant could be exposed to a dangerous and unexpected discharge of steam in the event of a water heater malfunction. I noted in the report that corrective action was immediately required. I also indicated that the extension pipe should extend to within 6 inches of the floor.
From this article: https://www.nachi.org/tpr-valves-discharge-piping.htm?loadbetadesign=0
Should be constructed of an approved material, such as CPVC, copper, polyethylene, galvanized steel, polypropylene, or stainless steel. PVC and other non-approved plastics should not be used since they can easily melt.
Lost puppy
You are correct but I have an additional question. It appears the pipe that the TPRV is attached to goes somewhere else. Is this a tankless water heater? Looks like the pipe is 1" with a 3/4" to the TPRV. Only reason I ask is if Tankless the valve is Pressure Relief Valve most likely. Can’t tell where you are located but on the Tankless water heaters I see here in CA there is a specific location for the PR Valve at the bottom of the unit. What I find frequently is non-permitted installs where the PR valve is not installed at all.