Intensity problem

Posted by: Florin

Intensity problem - 11/17/15 02:48 PM

I have a problem with an air blasting machine on the last two weeks, I can’t reproduce the saturation point on the almen curve I am always over the saturation point with 0.03 inch and I don’t know the cause

Please, can someone help me
Posted by: Jack Champaigne

Re: Intensity problem - 11/17/15 04:04 PM

I need to ask several questions first:
1. Has there been any recent maintenance on the machine, especially the blast hose or nozzle?
2. Are you running a full saturation curve (i.e. 4 strips and solver)?
2. Is the air pressure OK? Has the regulator been certified recently?
3. Has there been any change in media (i.e. different supplier, different hardness)?
4. Is your "error" actually 0.003 inch (did you leave off a zero)?
5. Did the change occur gradually over the past two weeks or all of a sudden it was off by 0.003"?
6. Have you checked the Almen holder flatness?
7. What is your target intensity?
8. Were you able to achieve this intensity for a long time?
Answers to these questions might lead us to a solution.
Posted by: Florin

Re: Intensity problem - 11/17/15 05:00 PM

Answer to your question

1. Three month ago and the hose i change them last week
2. Yes
3. Yes I verified him last week and yesterday and is in 0.5 PSI deferent from the target
4. Yes it a new Bach but I verified the hardness of the media ant is conform
5. It is 0.003’’ different
6. The change occur sudden two weeks ago
7.Yes it was verified by mi supplier last week
8.the range intensity is 0.014’’-0.018’’
9. Yes I was able to achieve this intensity in the last 6 years

I had problem before with low intensity but with higher intensity never

Thanks and have a good day
Posted by: Florin

Re: Intensity problem - 11/18/15 02:19 PM

It is someone it can help me with my problem
Posted by: Jack Champaigne

Re: Intensity problem - 11/18/15 02:51 PM

1. Was there any difference in the blast hose?
2. Is it the same material, same thickness, same supplier, same length of hose, same type of fittings?
3. Did the intensity change right after you changed the blast hose? If the new blast hose inside diameter is larger it will have less pressure drop towards the nozzle and this will give higher velocity and therefore higher intensity.
4. What about the Almen strips? Are they the same supplier and same lot number?
5. I presently suspect the blast hose as the problem but there could be another cause. What is the size of the blast hose (inside diameter) and what is size of blast nozzle?
6. What is your air pressure setting?