Is retro-fitting a Primus pump possible?

Doc, the 1/8" pipe thread is not 1/8", it is more like 3/8" (.375")

Look at the image I posted above. It shows the 1/8" x 28 tpi is BSTF and BSPT.
NPT is 27 tpi. The guy at ACE seems to be incorrect.

An 'R' drill should be quite easy to purchase, but not at ACE.

Why would a Non-American made pump have an American thread?

 

Hey, Afterburner, Longilily, and Snwcmpr,

Thanks, Guys, for helping me cool down and tad, and for your excellent info and suggestions. Yes, I looked at the chart, and it does show 27tpi for the US pipe thread. According the gauges I just bought, the 28tpi seems to fit better than the 27tpi. I'll measure again, under very good light, and a huge magnifying glass, and double check that. I also agree with Ken, when he asked, why an American fitting would be used on the overseas pump connection. Longilily made pretty much the same point, and it is well taken from both of you Gentlemen.

Ray, please wait on sending anything, until we get it sorted out completely. Plus I will be sending you something on Monday, and we can combine Postage if we hold off for just a bit on you sending anything. Ken, many thanks for offering to do this work, just as Ray did!! Much appreciated on both counts, Guys!!! I may take one of you up on your kind offers, but I also see the value of my learning to do some of these tasks, myself, after learning a bit more about them. Talk to you all later. Got to shut down this danged confuser, and get some work done. I'm way behind!! YIKES!! Thanks again, take care, Merry Christmas, and God Bless!

Every Good Wish,
Doc

 

Doc,

What's confusing is that with bolts we focus on OD. With pipe fittings and tubing its ID. Wall thickness and OD for pipe fittings is happenstance of the pressure that they would be subjected to.

Glad you made a positive match

AR

 

Pazte

Ok Doc

 

Hey Doc,

No worries! We just have to push forward and all challenges will be won!

Fettlers speech that is quite similar to a speech of one UK prime minister just keeps us working until solution is found:

We shall go on to the end. We shall fettle in work shop, we shall fettle in the shacks and yards, we shall fettle with growing confidence and growing strength in the hardware store, we shall fettle our stoves, whatever the cost may be. We shall fettle on mornings, we shall fettle on noons, we shall fettle on afternoons and evenings, we shall fettle on nights; we shall never give up!

 

Hi @Doc Mark

I discovered this post recently. I was looking for a solution for the same problem: How to connect a PRIMUS pump to a Cejn connector. I use to carry a Dragonfly stove in my bycicle journeys. As you know Dragonfly is one of the best expedition stove with the worst pump! My idea is joint the Dragonfly to the Primus pump.

I've a Primus Varifuel pump (Himalaya series) similar like your. I expect to find the way for join the Cejn connector to Primus pump in some days.

I will keep you informed.

 

Hi, @pau-i-amor ,

Thanks, Pau! I finally just gave up on trying to understand all that stuff, and figured I'd wait until I could get to a real Hardware store, instead of Ace. I'm eager to hear what you find out for your own conversion, my friend!! Thanks for giving me a shout! Take care, and God Bless!

Doc

 

This seems to be an ancient thread come to life - but the subject is interesting. Looking on the CEJN website they quote
Couplings
Male thread
Female thread Part No.
Connection
10 141 1251 G 1/8"
10 141 1201 G 1/8"
Nipples
Female thread Part No.
Connection
10 141 5201 G 1/8"

According to Wikipedia G 1/8" is 1/8" BSP parallel

Regards
Murray

 

@Doc Mark, I wish you resume your challenge.

I spent a long time looking for what kind of thread has the PRIMUS aluminum block pump series.


First. Both sides of aluminum block has a different thread.
Second. No metric, no BSP, no Withworth, no UNF... Maybe no standard... at all!



It's a SCHRADER thread! I think this will make things easier. Male thread: OD, 7.7mn pitch, 32 tpi.



If you buy this schrader long thread valve, you can take advantage using the cuore of the valve as a NRV and avoid leaks...

In the other hand, Schrader has a lot of devices we can check...
Válvulas

 

@pau-i-amor
I suggest a CEJN fitting’s the way to go. 1/8 BSP threads tapped into brass connector block silbrazed to a Primus valve.








With another adaptor, connection of Primus pump to MSR offerings is possible too.

 

Wow... very cool

Regards

Murray

 

There are two ways.

1.- DRILL (enlarge) a 11/32" hole in the aluminum block and make a new 1/8 BSP thread.

2.- Look for an adapter from Male Schrader to 1/8 BSP (male o female)

... and then connect with the CEJN 141 serie connector.

 

@presscall

Thanks, John.

I start with this: a Himalaya serie pump, without any connector.

 

I would like one of those valves. Are they available now?

Ken

 

@snwcmpr
It was originally the valve on a Primus Omnifuel flexi-hose Ken - the earlier type with a thicker hose (than on later generations) that accompanied the type of pump in those photos. A later version valve would’ve done too. It had to be made of a metal that could cope with the heat of silbrazing, so those cheap valve/flexi-hose products from China wouldn’t serve, since part of the valve is made of aluminium.

Knob, spindle and O-rings had to be removed from the valve before taking a blowtorch to it of course.

John

 

@presscall Thanks.
The ones I have and have seen cannot be soldered.
Still looking.

 

I just recieved an email from my local CEJN dealer. Although in the CEJN website you can see only three references, other 141 series elements, as two pointed with red arrows, can be delivered on demand. Keep calm! You would wait 4-6 weeks.

 

I said: "@Doc Mark, I wish you resume your challenge"...

and There are two ways.

1.- DRILL (enlarge) a 11/32" hole in the aluminum block and make a new 1/8 BSP thread.

2.- Look for an adapter from Male Schrader to 1/8 BSP (male o female)

The original Primus Varifuel / Himalaya series thread is a Schrader thread (see above).




I enlarged the pump hole, drilled a 11/32", 7.7mm Diameter. How deep? I think no more than 17mm.







I made a new thread with a 1/8" thread tap.



BSP or G 1/8" 28 tpi. Remember to throw some drops of oil when you work with a thread tap.



Clean carefully the thread!



This is a Camozzi 1/8" junction. It's cheaper and a little bigger than CJEN junction.







I visited a local workshop for change the MSR Dragonfly hose.



Yes! They use to sell spare parts for trucks, caterpillars, tractors, bulldozers... and this is the thinest hose they have...



Nevertheless it's more flexible than the original MSR Dragonfly hose.



It runs ok!



The hose is too much thick. Even I turned the botle, and waited all the air pressure flowed to the burner It falled down some drops of fuel when I took apart the junction.



I think: There are three points for cut the fuel flow. 1.- The pump spindle. 2.- The junction 3.- The flame control



Maybe it would be a good idea to turn the junction upside down, with the coupling in the hose side and the nipple in the pump side. Then, when you turn off the pump spindle and take the nipple apart no fuel drops fall down.

 

@pau-i-amor
Wow / I bow to the worthy!!

 

Hello, @pau-i-amor , Pau,

Many thanks for taking the time to share your experiment! Looks like it is certainly do-able! As soon as I can dig out that Primus pump, I’ll see if I can locate the needed parts, and will try to make this happen! Thank you, very much, my Good Friend!! Very well done!
Best to you and. Your wonderful family!!

Every Good Wish,
Doc