# WeeBee pop valve question



## ChaoticRambo (Nov 20, 2010)

I recently purchased and installed a new weebee pop valve set for 60 psi for my Accucraft Mogul.

After installing it, and running it for the first time - I have a few questions. Since I have not been around anyone to observe one of these closely, I am not sure what the norms are.

The first thing I noticed is that it seems to leak a lot of steam. I was not expecting this. During steam up and while running, there is a consistent stream of steam coming from the pop valve (not from the location of where it is screwed together or into the boiler). 


Another thing I noticed is that it doesn't consistently pop at 60 psi. While working with the locomotive stopped during the run, I notice that it popped a few short times between 40-60, and then didn't pop at all until around 70 psi when it finally started to fully pop.

Is this normal, as I truly don't know?

Thanks,

Patrick


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## RP3 (Jan 5, 2008)

No, your results are not normal. Get in touch with the owner, Jim Saunders, at (317) 931-8392 and I'm sure he can take care of the problem. I installed one of his safeties in my K-27 and it worked perfectly from the git-go. 

Ross Schlabach


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## steamtom1 (Jan 2, 2008)

Sounds like it might be a speck of debris stuck in the valve. Under steam, lift the valve stem with a pair of needle nose pliers to clear out anything that might be lodged therein. A properly functioning WeeBee should sound like this...


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## jfrank (Jan 2, 2008)

I have Jim's pop valves on some of my engines. They work just great. Making a pop valve is something of a 'black' art. If it does not funtion properly just send it back and Jim will fix it.


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## David Leech (Dec 9, 2008)

John, 
I don't 'think' that there is a black art involved with Ross "pop" safety valves! 
It's just that the ball has to sit in a hole the same diameter as it, so that steam is released violently and quickly when it lifts. 
On a small boiler, I would imagine that the sudden release can mess up the boiler pressure sometimes. 
Also, with a boiler that is fairly full, they will tend to blow some water unless the steam is entering from the side if the safety valve, as again the violence tends to suck water. 
I much prefer a gentle release of pressure to maintain a constant boiler pressure when running, ideally with it never lifting as the burner is producing just the correct amount of heat. 
I know, it looks good when the safeties make a lot of noise and blow off all the time!!!!! 
All the best, 
David Leech, Delta, Canada


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## jfrank (Jan 2, 2008)

Posted By David Leech on 19 Feb 2012 09:41 AM 
John, 
I don't 'think' that there is a black art involved with Ross "pop" safety valves! 
It's just that the ball has to sit in a hole the same diameter as it, so that steam is released violently and quickly when it lifts. 
On a small boiler, I would imagine that the sudden release can mess up the boiler pressure sometimes. 
Also, with a boiler that is fairly full, they will tend to blow some water unless the steam is entering from the side if the safety valve, as again the violence tends to suck water. 
I much prefer a gentle release of pressure to maintain a constant boiler pressure when running, ideally with it never lifting as the burner is producing just the correct amount of heat. 
I know, it looks good when the safeties make a lot of noise and blow off all the time!!!!! 
All the best, 
David Leech, Delta, Canada 



LOL David. Thanks for the lecture. But I agree, the optimal way to run the engine is with the pressure sitting just before the safety opens. These engines I see with steam just pouring out of the safety valve are wasting a lot of fuel and water. But I guess they like the looks of all that steam escaping.


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## HMeinhold (Jan 2, 2008)

Making pop valves "pop" open is not very difficult; David described how to do it. More complicated is keeping the hysteresis small and make it "pop" close. Dennis has done some experiments. A small exhaust opening helps to achieve the fast closing. However there is a trade-off between sharp closing and avoiding dangerous overpressure. With my Guinness I was lucky, the safety valve usually opens/closes within less than a second.
Regards


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