Dear all

I was just looking through AMS 2430/2431/2432 and they don't seem to specifify the use of spiral separators for monitoring roundness checks, but this is pretty common component for controlled shot peening systems. Is there any specific requirement with respect to how much of it should go through a spiralator? It s not compulsory so some do not need it , but some require a small portion of the media stream to go through it and some require 100% of the media to go through it. My question is

1) If a system has spiralators incorporated , does it mean that there s less/no need for visual inspections for irregular shapes.

2) does this help with Nadcap audits

Adam,
you are correct, spiral not required normally (perhaps in private specs). It will not affect nadcap audit frequency but will certainly improve media for more assurance of passing audit. For air-blast equipment with just a few nozzles all of the media could go through sprial but the flow capacity is limited. See the new Profile Industries sprial. They do something very cleaver. They rotate the spiral thus improving on thru-put.

Profile Industries Spiral Separators

Spiral seperators are an effective method for removing broken shot particles and very irregularly-shape particles. AMS2430 specifies limits of 1, 3 and 5% of broken particles - depending on application. With respect to your first question there must always be a need for visual inspection - in order to satisfy the relevant specification. Visual inspection test results will allow assessments to be made of how much separation is needed.

Thanks Jack, Socrates,

Just curious, with regards to "Visual inspection test results will allow assessments to be made of how much separation is needed". Supposing I m to use steel shots in accordance to AMS2431/1. That s for new media and if I remember correctly, visual inspection of unacceptable shots is 1%, I find that I have 2% of unround shots. How do I assess how much of in-use media is required to go through the spiral separator. Is there any spec for or any common industrial practice here?

Adam

IF your spiral separator was 100% efficient then the obvious answer would be that at least half of your in-use shot would have to be processed. Separators can never be 100% effective so best advice is to test your separator's effectiveness on a good-sized sample and then do the corresponding sums.

Thanks socrates for the advise

Spiral separators are also not effective with small to midsize glass bead. We have the above mentioned Profile Industries device and I can tell you that it works very well.
We use it mostly for 70-330 Cast steel. Conditioned Cut wire basically does not fracture so running it through a spiral is generally not needed.

Thanks Walter, that s good to know. Any reason in particular why you don't use it for media larger than 330? We most prob use s550 for peening of landing gears, that's why I m asking.

PS: This forum is great by the way

Better late then never. We simply don't use any media above 330 in size.