[Braehill]

Was just there this morning, it's about an hour down the river from us. I can get the number from our catalog, but thanks.

Len


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[Rick_H]

Looking good Steve! I've also never seen a bronze muffler that big...

6013 runs like butter, I don't see any issues with what you did at all. I assume your flipping the frame to keep welding flat...vertical with 6013 is not fun.

[Otto Nobedder]

Was just there this morning, it's about an hour down the river from us. I can get the number from our catalog, but thanks.

Len

Good. I forgot to hunt the part #. They are used in every vacuum jacket vessel application I've yet encountered with your company, so should be easy to find. For the LHY trailers, search for the description "V-7". This may bring up two part #s, one is a Key-High valve, and will have a "V-7A" associated with it (as they're used in pairs). The other is the Male X Female Hoke valve. They have a different description for the atmospheric trailers, "VV-something" that I don't recall, but can find for you, if needed.

Steve S

[Otto Nobedder]

Looking good Steve! I've also never seen a bronze muffler that big...

6013 runs like butter, I don't see any issues with what you did at all. I assume your flipping the frame to keep welding flat...vertical with 6013 is not fun.

I did a lot of flipping, to keep the welds flat, but I did several uphill, and a few tacks downhill. 6013 up is different, but not hard.

You can have those mufflers custom built to almost any size, with any size sintering to control filtration. We were not prepared for the cost of custom pieces when the stock item from McMaster would be adequate.

Steve S

[Antorcha]

While I'm not a fan of 6013, and refuse to use it, you did one heck of a job! As to be expected, of course.

If y'all would quit trying to use 6013 as // " ona them thar dragggin' rodzzz" and hold an arc with the thing you might not hate them so much. You hold an arc and crank it a bit and they'll penetrate. Go head. Up one ten-15 amps from 'normal' and hold an arc.
Drag it when welding a Nascar wing to the ol' lady's 5 color Opel GT. Then it works like a redneck MIG replacement.

[DLewis0289]

For you all in the know, the Asco is energize to open in this application, what you call fail to safe engineering

[Otto Nobedder]

For you all in the know, the Asco is energize to open in this application, what you call fail to safe engineering

Exactly. The pump has a built-in anti-backflow valve, but it's not always reliable. The Asco is redundancy. If the power fails in the night, the valve closes, and the main contactor opens. Neither the valve nor the main contactor can restart on it's own when power is restored; It must be restarted manually. This protects the process from significant vacuum loss, as well as from sucking oil from the pump into the process.

The hand-wheel valves I was waiting on finally arrived, and the first pump is complete, minus some minor bracketing to store the hose used to attach it to it's service, and the paint touch-up coming from doing that. I'll post a "finished product" picture, probably tomorrow. The second pump shipped Wed. morning and I'll probably see it Monday. Round two will go much faster, as they're identical and all the issues were resolved on the first one.

I dislike designing equipment when I don't have all the information on all the parts, so there was some "adapt and overcome", but it worked well, and will repeat well.

Steve S

[Otto Nobedder]

Finally have one done and tested. When the other pump arrives, all the components are pre-made and it will be (fairly) simple assembly and wiring.

These are hi-res shots, as my little camera ran out of battery, so I'm linking my dropbox locations for them... I won't know if they'll show until I submit the post. [Edit: whaddayaknow? It automatically resized them!]

2016-05-20 13.28.23.jpg (48.99 KiB) Viewed 2815 times

2016-05-20 13.28.45.jpg (48.35 KiB) Viewed 2815 times

Steve S

[DLewis0289]

Damn nice job! I am guessing that is an hour meter next to the start/stop, what is a above it? Digital vacuum gauge? Do they need to pull all the way down to 29 inHg ?

[Otto Nobedder]

Thank you. I was very pleased to have free reign to build it however I wanted it, since I'm the primary user. My design objectives were compactness (our old ones were much bulkier), low maintenance, easy hose and cord stowage, and easy to roll around (the complete pump/cart is right at 1000 pounds). The 3" pipe is mitered 18* to cant it away from the pump because there's a lifting-eye that the pipe would have been in the way of if I'd kept it straight (something no one thought of on the old pumps). If I've built it right, that eye should be at the center of gravity, though I've not tested that yet. (Sometimes, the overhead crane is the easiest way to put it where I want it.)

That is indeed an hour meter. The object behind it is actually just a rubber lined plate (the thermocouple for the vacuum gauge is sticking up behind the mated flanges). The 1 1/2" valve is obviously the main vacuum valve, the smaller valve on the left is for attaching a mass-spectrometer for helium leak detection, while the one on the right is for breaking vacuum using dry nitrogen. The plate is a safety device. The N2 is supplied through the small ball valve behind the tee, while the plate blocks the open leg of the tee. When the vessel reaches atmospheric pressure, the plate drops off, keeping anyone from accidentally creating positive pressure. In a vacuum-jacket, positive pressure in the vacuum space can crush the inner vessel.

You likely can't see in the picture, but the plate is attached to the tee with a small stainless wire, so it can't vibrate off the pump and disappear while it's not being used.

These pumps are capable of pulling to below 1 millitorr, though in our application we rarely need to get below 5 millitorr. While this is still classified as "rough" vacuum, it is almost 29.92"Hg.

Steve S

[DLewis0289]

Rough at 29.92 lol, not going to get much better in our world unless you take it to theory land. Critical processes that require vacuum has no room for "just good enough", PID control for pressure is a snap with a less than perfect vessel. I used to work on vessels that required both pressure and vacuum with large agitators, which of course meant there were two back to back either John Crane or Chesterton mechanical seals rigged in the stuffing box with a 3-4" shaft running through it. This was before the split seals, an issue meant pulling the entire reduction unit to repair. One of those clients you hate, super dick, but payed well and on time, so I was on top of tanks sometimes at 2:00 am doing the work.

[Otto Nobedder]

The semiconductor industry, research labs, and NASA are three places I can think of that go to medium and high vacuum. We don't have the coin or the need for that kind of pump. There's $25K in the one I built.

Steve S

[Otto Nobedder]

Yeah!

Those pumps are running all weekend.

We went from sitting on our thumbs to more work than we can handle over the course of three days.

Back in the saddle!

Steve S