The thread on my D.G.I. Filter seems tight when I try to use it, is that right?
This instruction for spanner joining and separation is only applicable when using the individually bought item D.G.I. filters only. If your D.G.I. Filter comes pre fitted to the UK bayonet, this is pre fixed and is not intended for removing.
Our GAS IT D.G.I. Filter have 2 threads of 21.8mm each - The external ( male ) thread that allows it to be screwed into a UK fillpoint, and the internal threat ( female ) that a European or UK fillpoint adaptor screws into.
You will notice it also has a pair of machined slots on either side of the filters body, this is for use when fixing the filter to one of the European fill adapters for safety in use.
The External ( male ) thread on the D.G.I. Filter has been manufactured to be a easy fit in to, and out of, the threads on the inside of your UK bayonet LPG point as fitted to the vehicle you are wanting to fill up with LPG / Autogas. It can be simply screwed in to the UK bayonet threads by hand and the filter seals on the vehicles existing fillpoint with the black rubber o ring. Once you have filled up with LPG, you simply remove the D.G.I Filter from the vehicles fillpoint by hand, as this thread is designed to be easy in and out.
The internal ( female ) threaded part of the D.G.I Filter has been designed with an interference fitted thread, which requires the use of a spanner ( thus the reason for the machined slots on the side) to hold it steady whilst the European Fill adapter is tightened into it - This then makes the European adapter and the D.G.I. filter become one temporary secured unit for safety reasons when filling up and also for easy of removal from the vehicles fill point after filling, as one complete filter and adapter unit.
We have had this interference fit thread included so that simple tightening together with a spanner meant the user was 100% sure this seal between both units was gas tight ( because the sinted bronze filter causes a little pressure increase on the adapter to filter female joint so we wanted a possibility of a leak here to be eliminated if the filter and adapter came apart ), with also the added benefit that when filling up in another country where confusion might occur, that there could be no possibility of the European fill adapter and filter becoming separated a little when filling up. When you have filled up and are now removing the 'complete European fill point Filter unit' after filling in one European country, the complete unit is quickly and easily removed from your vehicles fill point in one easy to manage piece.
When you move from one country to the next, its just a simple case of unscrewing say the French fill adapter from the D.G.I.Filter ( by using a spanner ) and then replacing the French with say the German adapter.