Spitfire Mk2 Petrol Tank Outlet

[Peter Truman]

Can anyone please tell me the thread of the union that screws into the bottom of the Mk2 Spitfires fuel tank I believe part No. 60176.

Reason I want to put a on off valve in there so I can isolate the tank and make replacement of the rubber hose to steel pipe easier, currently there are two flexible rubber hose pipe lengths in the boot and to remove replace I'll have to drain the tank or get a boot full of petrol. I only want to do that once!!

I have a good comprehensive selection of small dia hydraulic pipe accessories from my old work days, all of very high quality manufacture, so it should just be my labour..

 

[eddyinfreehold]

Pete, have a read of the thread below, "Spitfire Mk 3 Tank...Long Story" . It relates to my recent experience.

I took the cut off pipe, nut and bu88ered olive into several hydraulic engineers on our local industrial estate in a small city in North Lancashire. I found a bloke who gave me the time of day in the third place. I handed him the part in the attached photograph and in 2 minutes he came back with the fitting you can see attached to the new tank. Whether one is available with a reliable stop valve or tap I have no idea. Perhaps inserting a stock fuel valve in line separately might be a better idea. My experience of fuel valves/taps over time is that wear or seals fail and they weep. In the rare event you want to shut off the fuel I would just drain the tank and be done with it. Having spent a lot of time kneeling into my Spitfire boot I can recommend you buy two or three standard plastic washing up bowls for domestic sinks to receive the petrol as it drains away and have cans and a funnel ready to receive what you drain. Safety first.

In terms of the thread, and I am not absolutely certain, it is either a 1/2" BSP or UNF with the JIC 37 degree compression fitting. The JIC fits wonderfully and makes a great seal. They may actually be the same or very close threads. By the sound of it you may well have parts in your inventory. I hope this helps. It is not absolute but it will be a lot better than trying to find an olive to fit your original nut and pipe. I'm certain Melbourne has a far better selection of hydraulic engineering suppliers than Lancaster or Morecambe. Great city ... would love to visit again.

Eddy

[NonMember]

I think it's 1/2"UNF. 1/2BSP is actually a much larger thread since the BSP size is the original bore of the (fairly thick wall) pipe that would take that as an outside thread. Achieving a good seal on the end face or with a taper thread may be challenging on an older tank, since the design is for an internal olive seal.

[eddyinfreehold]

That makes complete sense, thank you. Of course the BSP size is larger to fit the copper piping of domestic plumbing before 15mm became standard,

1/2" UNF then ...

[Peter Truman]

Thanks for the info gents it helps a lot, the valve I'll use would be a Whitey which is all brass with stainless steel working internals, which must be classified as the RR of hydraulic instrument & piping fittings of similar quality, all ex upgrade & renew of major pump station restorations, built for a lifetime of service. 

I have a good selection of brass 1/2in UNF unions and olives to fit the tank outlet. 

 

[eddyinfreehold]

Nice one. Once drained it's surely straightforward to test-fit finger tight first. When sealing for good other folks have suggested that a bit of care is needed tightening up to the female nut receiving the pipe and olive which is welded ... or possibly brazed... to the tank so as not to damage that connection. Really interested if you sent a photo of the successful union and tap.