Quick Set - Poppet & Seat Break-In Fixture? Reviews?

[kelemvor]

I don't know if this is nonsense or even applies to diaphragm first stages; but back in the 80ies one of the guys who taught me to rebuild regulators (ScubaPro) espoused the idea of "full stroke cycles." I.e. attach the first stage to a tank, turn the air on, then off and purge-repeat process 20-30 times.

Because I'm too cheap to afford the Quick Set device, and from habit, I still use a modified version of this process. I'll try to find a picture of my cycling tool.

Edit: Picture and quote from a long forgotten thread: Really, how much creep is a problem.
"....it is pretty simple. I bought a 175 psi pneumatic relief valve from Granger and put on a couple of adapters so I could screw it into a first stage l/p port. This way I can remove all of the hoses and conserve lots of air when I do the first stage cycling. Air on/air off/pull the ring, pfffft! One cycle."

View attachment 499916

You could automate the ring pulls fairly cheap with a servo and an arduino.

https://smile.amazon.com/gp/product/B07GPPK4DK $19 for 5 arduino nano's (this is my favorite nano since it has microusb connector)
https://smile.amazon.com/gp/product/B07BBQ5DXR $13 for 6 servos (with wiring and plastic hardware) That servo only provides 1.6 kg / 56.4oz of torque. You might have to get a slightly more skookum servo if it's not enough to pull the ring.

You'll only need one of each but it kills me to pay $7 plus shipping to buy an individual arduino.

If you've never used an arduino before, you'll probably be shocked to see how easy it really is.

 

[Colliam7]

I'm pretty sure there is no manual.
To change the four o-rings you just have to remove the center screw, pull out the pistons with the o-rings, clean the two cylinders, lube the the o-rings and the inside of the cylinders with Cristo Lube 129 or 111or something equivalent, put back the pistons into the cylinders and get the push rods aligned as it was (sometimes a bit tricky) and tight the screw.
To order the o-rings, contact Joan Howe from Scuba Tools joan@scubatools.com or info@scubatools.com and send a photo of the machine.
There is a newer and an older version, they use different o-rings in their cylinders.
Good luck!

Thanks. Seems like it is pretty straightforward. Since this unit has been around for a while, and still carries the Peter Built Co. tag, rather than a Scuba Tools plate, I will presume it is the 'older' version.

I will pay particular attention to the position of the push rods when I remove the screw. It is a pretty dusty unit and needs some clean up. Haven't looked at the O-rings yet, to assess their condition. Joan has always been very helpful and responsive to my email questions.

 

[jhawn518]

Well, that is not totally correct.

If the pressure continues to go down day after day (for several days or more), it can only be explained by a leak.


The pressure drop as a function of temperature drop (often referred to as Charles’s law) is part of what is commonly known as ideal gas law. Ideal gas law is one of the thermodynamic processes that is 100% reversible.

In other words, if you have a truly closed gas system (at constant volume), the pressure would go down when the temperature goes down, but it will also go back up when the temperature goes back up.

This up and down process is completely reversible and the relationship between pressure and temperature stays constant. This process and relationship is so repeatable that we have made some dial indicating thermometers that read temperature, but they are actually driven by the gas pressure.


I have been using this method for enough decades that I have a fairly good “empirical feel “ for the bubbles size and rate that I would expect to see. I have also done plenty bubble check to check for leaks. I actually have a high pressure hose that I can attach a first stage and dunk them in water without having to move a scuba tank.


BTW, some of the leak rates I am referring to can be as low as a bubble per minute or less (depending on location).

At one time I actually did some rough calculation of leak rates.

Some leaks should be located and repaired because they will get worse with time, but there are some minute leaks that can be easily tolerated.

Late to the thread but could you elaborate on the specifics of the high pressure setup you use to test 1st stages without moving/submerging a tank? Thank you!

 

[Luis H]

Late to the thread but could you elaborate on the specifics of the high pressure setup you use to test 1st stages without moving/submerging a tank? Thank you!

IF I want to do a bubble check I use this:

That is a high pressure hose with a yoke on one end and a pressure gauge. At the other end is a yoke valve fitting.


Most of the times I don't feel the need to get stuff wet and I just do a dry leak test.

If the leak is bad you can often hear it. If you cannot hear any leaks then I close the tank valve and see if the pressure drops with time. The amount of time I let it seat is proportional to high small of a leak I am willing to tolerate.

I often let it seat overnight (I am normally in no hurry) or for a few days. If the pressure drop is small, I don't worry about it. To me small (in an over night test) is dropping 100 psi or so when I started with something in the 2000 psi or higher.

Basically I close the tank valve the night before and sometime the next day I will look at the gauge and open the tank valve. I just look at how much the needled moved, if any.

 

[jhawn518]

This is very cool! Thank you for the pics and details!