I would like to know the differences between ASCO551 and 531 solenoid valves
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I would like to know the difference between the ASCO 551 and 531 solenoid valves. In our company, the wiring for the solenoid valves is as follows: DCS card – relay – 551 solenoid valve; DCS card – safety barrier – relay – 531 solenoid valve (the 551 cannot be used in place of the 531). Could you please explain why the 551 cannot replace the 531 solenoid valve?
This post was last edited by ssln123 on 2016-9-30 at 17:22. I’ve really never seen a DCS card–safety barrier–relay setup with two layers of isolation like this; the requirements are quite high.
The 551 series monostable slide valves come with IEC 61508 functional safety data certified by TUV, allowing for a safety level of up to SIL 4/AK 7; the 531 series does not have such certification. Thus, from a security perspective, the areas of use differ, even though the functions implemented can be the same.