Here is a picture of my single tier HERMS system.
Boil kettle on the left. HLT in the middle. MLT on the right.
Sight glass inbetween HLT and MLT to monitor the mash as it exits the HERMS coil during recirculation.
Sight tubes on the BK and HLT to indicate volume levels.
Fully plumbed with copper and stainless connections via tri clover fittings.
Built in oxygen tank and stone that are used as the wort exits the counter flow chiller.
BK and HLT are direct fired. The MLT on the right is not. Mash temperature is achieved via the HERMS.
Bypass valve on the HERMS coil in case temp starts to get a little warm during the mash.
One March 809HS pump.
You can look through the build here: