Upflow settling tanks, filtering, plumbing #14

 Upflow settling tanks are employed for cleaning diesel produced by the Orion retort. These are retired 100 liter LPG/propane cylinders. The object is to add fuel-for-settling to the bottom of the left tank which displaces already-settled-fuel which exits at the top of the right tank. The system works on the principle that the cleanest fuel is always on top. Fuel should stay settling approximately a month but subject to demand. A drain valve at the very bottom of each vessel allows water and contaminants to be tapped off. I painted the set up black in the belief that warming heat cycles from the sun may help settling.
Edit update 22Dec2014 I repainted these tanks to an off-white to help keep the tanks cooler. The thought is that fuel oxidation is reduced with the cooler temperature. I'm pondering over a simple sunshade as well.
Edit update 24Jan2015 I made simple sunshades for the settler and header tanks.

Drain valves for periodic sediment removal.

Bag filter housing with a 1µ nonwoven polyester filter-bag. This made from recycled 4" dairy tube and a RJT couplings.

Final spin-on fuel filter before storage tank. About 10µ. The housing is from a recycled Japanese diesel vehicle and the element is an old one from my van. It still passes enough fuel for this application which is about 4 ~ 5minutes per liter.
19May2014 I took a sample of diesel on May 1st from my storage tripod tank that had been through my settler and filters. It shows no sign of sediment after nearly 3 weeks. In addition the van is running well with no indication of its' filter plugging.
13June2014 I bought a filter suitable for gravity feed from my overhead tripod diesel tank. It's fitted with a 10µm filter element and uses 1" BSP fittings which is mainstream in this part of the world. Info snippet: Mr. Google tells me that 1" NPT is 11.5 TPI while 1" BSP is 11 TPI. 
3July2014 Latest filter trial using zeolite adsorbent which is a crystalline, hydrated aluminosilicates that contain alkali and alkaline-earth metals. Their structure is based on a three dimensional framework structure in a honeycomb network. The 3D-lattice work also gives zeolite a large internal surface area (up to 145m2/g). The housing is a recycled water filter with an added central pvc pipe that ensures maximum contact of diesel to substrate. The hope is that the spin-on bowl will facilitate easy swapping in of fresh adsorbent.

5July2014 Upgrades to the double upflow settler tanks allow controlled feed at a drip rate that reduces disturbance inside the settler. It's running at about 140 drips per minute as I write.
Pic taken just after welding the in and out sockets for the hose fittings
The header tank plumbed up to the settler. With a full header tank, I want to set a drip rate so it takes 2- 4 days to empty.

This where the diesel goes into the settler. The brass gate valve is used for flow restricting and controlling drip rate.
(Update, this method of flow restricting did not work very reliably so I've started using a Martonair needle valve where the flow drips into the receiving vessel, downstream of the settlers.) 

A bracket to secure the overhead header tank.