PRIMUS 8842 BURNER

[RICHARD GREEN 2Participant @richardgreen2]

[RICHARD GREEN 2Participant @richardgreen2]

I've got the recommended Primus 8842 burner for the hot tube on the Alyn foundry 1/2 size Gardner gas engine,

Does anyone know what the thread in the burner is?

Also does anyone know where I can get fittings to connect to say 1/8 copper tube ?

Thanks,

Richard.

[Steven VineParticipant @stevenvine79904]

Hi Richard

I just measured the male thread on the neck tube, and the male thread on the jet.

Mine are pretty old and worn so I get varying readings.

It looks like a 0.75 pitch.

The thread diameter measures just under 8mm (0.302inch to 0.31inch).

I think it is an 8mm x 0.75, but best to get confirmation.

Steve

[Michael GilliganParticipant @michaelgilligan61133]

Richard,

For thread size, see the neck-tube details, here: **LINK**

https://www.powertoolsdirect.com/sievert-neck-tube-valve-gas-torch?utm_source=google&kwd=&utm_medium=merchant_pla&gclid=COzQ57Kw_tACFcsp0wodGLYMTw

MichaelG.

.

Which confirms Steve's measurements 

 

Edited By Michael Gilligan on 18/12/2016 18:43:41

[RICHARD GREEN 2Participant @richardgreen2]

Thanks everyone for your comments and help,

.75 pitch works out at about 33 tpi, perhaps I could run a 5/16 x 32 tap in the burner for about 1/2", and then use standard 5/16" x 32 pipe connectors,

What do you think ?

Richard.

[Another JohnSParticipant @anotherjohns]

Hi Richard;

M8x0.75 – I purchased some metric fine taps from Tracy Tools – (no connection other than as a customer) – why not get the proper tap?

Just my opinion, for what its worth – John.

[RICHARD GREEN 2Participant @richardgreen2]

Hello John,

I understand what you are saying, The burner is already threaded, my problem is getting fittings for the m8 x .75 thread in the burner,

I can get 5/16 x 32 fittings anywhere, off the shelf to fit 3/16" copper pipe.

Richard.

[Another JohnSParticipant @anotherjohns]

Richard – Oh, ok. I make 100% (or, close to) of all my fittings, elbows, hex material etc, as it seems that nothing is off the shelf where I live, so pardon the myopia.

Good luck – John.

[RICHARD GREEN 2Participant @richardgreen2]

What I've decided to do is, screwcut a brass screw in the lathe M8 x .75 pitch, and then make a "banjo" type fitting that can be silver soldered to the 3/16" copper gas pipe, the whole lot will then attach to the Primus burner,

Sound like a good idea ??……………………………..Or not,

Richard.

[duncan webster 1Participant @duncanwebster1]

If it were mine I'd make up a barrel union with male M8*0.75 one end to fit the burner and 5/16*32 the other so you can use conventional nuts and olives. Of course you might not have room

[RICHARD GREEN 2Participant @richardgreen2]

Hello Duncan,

I see what you are saying, unfortunately the burner sticks out quite a long way already as you can see in the following pictures, I would like to keep it all as short as I can, so the engine is as compact as possible, using an elbow or a banjo fitting will do that.

Richard.

[Alyn FoundryParticipant @alynfoundry54186]

Hello Richard.

lovely work! I can confirm that the thread size is M8 by 0.75 mm pitch. I used to make a Brass Banjo coupling to convert to the readily available 3/16" Copper pipe sold for brake pipe repair. This also helped because Wade made many 3/16" compression fittings.

Cheers Graham.

[Keith HaleParticipant @keithhale68713]

Michael,

Concise and to the point.

Nothing more needs to be added.

Keith

[JasonBModerator @jasonb]

Bit late to this old thread but you can also remove the stainless steel end to reveal a M10 x 0.75 thread so the burner end can be replaced with something shorter (or longer) too.

The actual jet 2nd from left is the only original part left on my IF Allman burner

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