Author Topic: Fuel tap threads  (Read 2918 times)

Bob Purton

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Fuel tap threads
« on: August 19, 2013, 07:43:14 pm »
I'm having trouble understanding fuel tap threads. I have a Forge alloy fuel tank with a male thread on the underside as an outlet. The outside diameter of this thread is 5/8" od. A messerschmitt fuel tap scews straight onto it. I'm needing to establish what the thread fitting is because I want to fit a strainght forward outlet spigot to it as I'm going to use an electric solenoid valve instead of a fuel tape. Its probably a BSP thread but I'm unfamiliar with these. Can someone clue me up please?  Thanks.

super-se7en (Malc Dudley)

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Re: Fuel tap threads
« Reply #1 on: August 19, 2013, 11:07:24 pm »
It will be 3/8" BSP (16.7mm dia)
Ebay has all the varieties with elbows, reducers .male to female etc.
Hope this helps.

Bob Purton

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Re: Fuel tap threads
« Reply #2 on: August 20, 2013, 09:15:05 am »
Thanks Malc. I measured the tpi last night and its 26. Does that fit in with your analysis?

super-se7en (Malc Dudley)

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Re: Fuel tap threads
« Reply #3 on: August 20, 2013, 02:33:16 pm »
I am afraid 3/8" BSP has only 19 teeth per inch.
I can check tomorrow what 26 teeth and 5/8" dia might be if you like.

Bob Purton

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Re: Fuel tap threads
« Reply #4 on: August 20, 2013, 04:16:12 pm »
That would be much appreciated. Thank.

Rusty Chrome (Malcolm Parker)

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Re: Fuel tap threads
« Reply #5 on: August 20, 2013, 06:22:11 pm »
BSC Looks like the only 26tpi 5/8" thread. Some BSP 5/8" compression fittings have 24tpi.

http://www.britishfasteners.com/threads/bsc.html
Malcolm
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Bob Purton

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Re: Fuel tap threads
« Reply #6 on: August 20, 2013, 09:51:17 pm »
Thanks for the offers of help on this but I think I have cracked it. Its 16mm x 1mm pitch which turns out to be a recognised fuel tap thread.