So to test out the mod, the first thing I did was put a few Iron Ingots in a Pressure Chamber. I went ahead to test out some other things and when I came back to the chamber, they were gone. At first, I thought that they had despawned, but after 3 tests, I realized that they disappear once the arrow reaches 1. I have yet to test it with other items.

Just to be clear, you put the ingots in an unpressurized chamber and then raised the pressure, right?

I'll do some testing on this..

I believe that there was a bit of pressure in it so start with.

Hmm. Do you have an interface in this pressure chamber? Because as soon as an extraction interface (one with the 'I' facing into the chamber) gets enough pressure it will pull whatever is in the chamber out. It doesn't distinguish between ingredients and finished products - you have to filter it, and/or use redstone to control when it pulls.

Having just tested, I found the iron ingots vanished just as you said - but they were in my extraction interface all along. I haven't been able to make any item vanish completely.

Nope.

OK, I don't know what to say then. I can't reproduce it at this point.

Could it still be the items despawned? Have you put in an 'Item Life Upgrade' into the Pressure Chamber to make sure?

Nope, they were in there for less than a minute and it always happened once the pressure reached 1bar.

Any chance of some images or even a video of your setup? Might make it easier to reproduce.

Any updates please? This can't be reproduced, I really need to see what your setup looks like.

This is my setup:

The first time I tested it today, it reached 1 and 1/3 the bar became green again, but the ingot were still there. When it reached 1 and 2/3 they disappeared. Should I have mentioned that I always put a full stack of Iron Ingots in?

The second time I tested it, I started using the Manometer and it seemed that the ingots disappeared when the pressure reached 1.8bar.

The third time I tested it, it worked, but it only gave me 3 Compressed Iron Ingots from that full stack of Iron Ingots.

On my 4th test they disappeared when it read 1.2bar.

On my 5th test they disappeared when it reached 1.5bar.

I honestly don't know. I've tried everything and I cannot make any ingots disappear under any circumstances, regardless of pressure. And you definitely have no interface in this setup?

And what other mods do you have installed? Can you test this out in a minimal instance with as few mods as possible?

Also, can you please use a recent build from http://jenkins.k-4u.nl/job/PneumaticCraft-Repressurized/? No specific pressure chamber changes have been made, but it would be good to be level with current development right now. A lot of other fixes have gone in since the build 47 alpha release.

I could still use a mod list here...

Working on #52, which is expected to resolve this, as we will be getting rid of any item entities.

#52 is merged to master now, and should make this a non-issue since items in the chamber are not entities any more.