I've got a direct cylinder and no problems with what you've put.
Just some other comments ...
Might be better titled "Processors - using Hot water cylinders" or "hot water cylinders as processors" or similar.
To try and maintain an international bent, you could point out that this is a UK HWC, US cylinders are different but can be used for the Appleseed design.
... occupies some of the cylinder's volume and two connections which could otherwise be used as processor connections.
If using a second hand cylinder, check the integrity of all the connections, if they look dodgy it may be safest to find a better cylinder. If the cylinder is sound, check for lime scale. Once the cylinder has dried internally, this can be heard inside when the cylinder is shaken. As much limescale as possible needs to be removed, as any lumps left in the processor could cause damage to the circulating pump and block the venturi if you fit one.
I didn't take any other photos of the connections I'm afraid, but descriptions are as follows ...
The slanty one ...
To fit a connection vertically through the sloping bottom of the processor a brass compression fitting was used. An elliptical flange with an elliptical hole to take the fitting was cut from a piece of opened out, scrap copper tube. The flange was then silver soldered to the fitting at the appropriate angle. Silver solder was used so that the assembly could then be soft soldered to an elliptical hole in the processor top. (one photo shows the fitting in the processor with the flange silver soldered in place. The second shows the fitting and flange assembly soft soldered to the processor). If you want to mention it, just visible in those photos is am immersion heater socket soldered to the dimple (the flange is almost a perfect fit in the dimple) as an access point or a connection for future developments.
The one in the side of the cylinder ...
The foam lagging was carefully cut back and a hole drilled for a standard tank connector. A piece of wire was fed through the immersion heater hole until it poked out of the new hole. The internal half of the tank connector without the rubber washer, was then slid down the wire and pulled out of the hole. The securing nut was tightened on the connector and the whole assembly soft soldered in place. The foam lagging was pritected with wet rags during the soldering process.
Soldering gives a far better seal than just relying on the washer to make the seal. The washer is likely to be made of a material incompatible with Biodiesel.
Also we could mention insulation, in that the top of the processor needs a good layer. I can do additional graphics showing a standard foam lagged cylinder and a graphic and description of how I used polyurethane foam to insulate the top. It's all been cut off now but I might have some old photos I could dig out.
I'm sure others could contribute alternative versions of the top insulation too.
Sorry it's a bit long winded, but you did ask!
