Enders pump gaskets

I had some issues with my 263 Baby Enders stove and understood RussenJesus was the man to contact. I contacted him through this site, and he sent the gaskets out to me in New Jersey. The gaskets are top notch and shipping was very fast also. When I got the gaskets, I didn't know where they all go to. I found that info last weekend but just want to say-If you want a top quality product RussenJesus is the man!

 

@Russenjesus
A good man to deal with, yes sir.

 

Hi, this old post shows where the washers go on a typical Enders stove pump:

https://classiccampstoves.com/threads/enders-pump-service-pack-sefas.20506/#post-210662

Best Regards,
Kerophile.

 

Interesting Kerophile-I will look today at that tiny o -ring as it is in the package. Thank You!

 

Yes I took pump apart and saw where the o ring goes by the pump cup. I first thought it was a clip because it was flat and didn't know until I removed it. The o ring was torn and now replaced by a new one.

 

Hi @8R Pete The Enders pump depends on the very small O-ring to make the seal on the downstroke of the air pump.

The majority of classic European pressure stoves and lamps incorporate a tapered section on the pump shaft, and a matching taper on the bore of the pump piston, which seal on the downstroke:

https://classiccampstoves.com/threads/typical-pump-assembly.14026/

You should notice a big difference in pump performance on you Baby Enders with the new O-ring in place.

Best Regards,
Kerophile.

 

Yes big difference in the stove with the new o ring. Boiled some water today for beef bouillon cubes. Performed without flaws.

 

@kerophile

Hi, where is the air by-pass on an enders pump? I can't find it. Is it the same system as a Swedish one?

Thank

 

Your question was answered in the other thread.

 

@snwcmpr
Could you find it?

 

Hi @JP2

I believe you have first to ask yourself how these pistons seal on the downstroke.

In the case of the classic brass stoves the machined central hole in the metal piston seals on a matching machined taper on the pump shaft.

In the case of The Enders piston assembly, the smooth eyelet of the piston seals against a Nitrile O-ring fitted on a groove on the pump shaft.

In both of the above cases you cannot have effective pump operation if these engineered seals are faulty since pressurised air will always find a leak path.

Now consider what happens on the up-stroke. In both cases ( Classic and Enders pumps) the pump shaft moves upwards relative to the “floating” piston, until the piston comes to a stop against the retaining nut at the end of the shaft.

However, there is no well designed air-tight seal at this end of the piston assembly/shaft and the air can pass via the centre hole clearance to the lower part of the pump cylinder. As Colin says, there can also be by-pass flow around the periphery of the leather bucket, but that is likely to be minor in a properly operating floating piston.

It only takes a very small clearance for substantial amounts of air to move past a piston under differential pressure. The stove makers found that they did not need to provide a specific “air by-pass” such as you seek. Normal leakage due to lack of a positive seal is sufficient.

I trust this helps.
Best Regards,
Kerophile.

 

General principle of a simple manual air pump:

The pump compresses air. When air in the cylinder is compressed, it is pushed from the cylinder into the fuel tank via the Non Return Valve (NRV) located at the base of the cylinder.
The NRV is forced open by the pressure of the air. At the end of the stroke, the handle is pulled up again, the NRV shuts off automatically so that fuel or air cannot escape from the tank, and new air is forced back into the cylinder so the process can be repeated.

 

Here on the picture, does air can go through when the eyelet touch the bolt on the pull back of the rod. Thank

 

YES, as it is not designed to be a leak-proof joint.

Regards,
Kerophile.

 

Thank you very much Kerophile

 

Does this help?

 

You bet !!!!!!! Colin, it is exactly what I needed to see. It make sense now. YES !!!!!!

Thank a lot

 

I used to create technical diagrams like this as part of my old job so I thought I'd create one to explain the theory.

BTW, if it was helpful for the site I could create more of this type of drawing to explain certain concepts. Maybe they could go in the reference library? I enjoy this kind of thing and I'm cheap (i.e. free!)

 

@Colin Geer

Maybe you should collaborate with @kerophile...

Tony

 

Hi, @Colin Geer . Amazing graphics and so useful on an International Site where English is often not the first language of many members.

“A picture is worth a thousand words” for so many people.
Best Regards,
Kerophile.