TXR - FLOW

[Max]

Who do you get to pressure test your rams?

[xtreme]

They dont have to be pressure tested. And even if they did they are far superior to anything you can get off the shelf.

[maddox10]

They dont have to be pressure tested. And even if they did they are far superior to anything you can get off the shelf.

9.7.1 Custom Components
Custom made components, or parts operating above the suppliers maximum working pressure, must be
independently tested and certified at 120% of the maximum system pressure available at that point.

[xtreme]

Nobody pressure tests there rams.

[team_mute]

Oh dear, how do you know they are safe if they aren't tested, we do material thickness calcs on our kit and still hydro them just to make sure.

Only thing you don't have to do as long as your not selling any type of pressure vessel is get it certified for P.E.D.

And if you are selling them P.E.D isnt a problem until you get into the certified body approval, for a CAT 3 job on our equipment we have to pay around £1200.00 for the certification, bit less for CAT 2, Cat 1 and sound engineering we can do ourselves in house

[Mouldy]

Flows ram isnt strictly a pressure vessel.. since its got a hole in the bottom to atmosphere, and a few holes in the top, the ram itself doesnt contain pressure.... unlike a normal commercial cylinder.

If you were to start making buffer tanks and selling them, then you should supply certification with each item sold to prove its been tested, true.

[team_mute]

The ram must hold pressure at some point else it would just vent to atmos even with a leak (I used pressure vessel as a generic term, we sell silencers that go to atmos and we still have pressure test, do calcs etc and PED stuff) the holes at the top I'm guessing are to vent the air from the top side of the ram.

Anything that holds pressure should be tested. In this case I would assume you are saying that the maximum working pressure is atmos due to the hole, even though it will retain gas at up to 40-55 bar?

Rams and buffer tanks would all full under P.E.D if you were selling them, all depends on pressure and size as to which CAT number it falls into.

[maddox10]

Nobody pressure tests there rams.

I do, and I have independents arranging paperwork if needs be. I can't afford any legal shit raining down on me because I made a mistake. I prefer a ram blowing in my workshop, than in the shed of an prototype tester.

@Mouldy,

any ram is a pressure vessel. Otherwise it can't work.

The Cutlet System (standard feather setup) uses an exit hole.
Now, to put it in perspective. The loathed Burkert 5404 has a let trough of 1/2 BSP =126mm²
An avarage exit hole is 1.5-2mm diameter. Lets take 2mm as example.

0.1*0.1*pi=0.0314mm²
0.0314mm²*55bar= 1.73 kg loss.

Meaning with warm gas entering the ram, you have a max of 54 bar. Dropping fast due abatic temperature differentation.

[xtreme]

That's assuming the robot was running full pressure. And to be honest we don't need a full pressure system to have a more powerful flipper than anyone else. Not being cocky but it's just fact.
So who's pressure testing these drinks containers being used as buffers and modified rams that show up? I bet 90% of the pneumatic robots out there have modified or custom pneumatic parts that havent been tested.If you want to get somebody to pressure test my ram feel free. But I can almost guarantee the ram in flow now is far superior to any other rams around that are custom made , modified or off the shelf, iv had a few rams that have been made by other people and none of them are no where near the wall thickness or strength of flows. Machined from a billet with no fixings in the 10mm thick top end cap to weaken it, you tell me what can go wrong. I'd be happy for you to test that ram at 200% or 300% of the pressure I'm running.
Our buffer tanks and anything before the valves will be pressure tested, thats mainly so I know I don't have leaks where the systems welded up etc.

[team_mute]

If your testing the stuff before the ram why cant you test the ram at the same time, as you've already said it will be fine so you've got nothing to worry about.

You just need the paperwork to back up your claims