Right above the rubber tee before the last piece of visible drain. That's an AAV.
What else do you see wrong?
I'm asking because I used that setup in my kitchen and want to know what I need to change and why?
If you would be so kind.
Thanks in advance.;)
You still out there?
I was talking to a printer friend one time because he had made an error on a publication and I needed to have him reprint a page for insertion. He showed me a book for a professional society and told me it had 35 closely spaced PAGES of errata that had to be inserted as an addendum with references. Few books, regardless of extensive proofreading, are error free. And given that "how to" books are usually quickly written by less than professional authors, and then proofed by readers who do not know the material, then printed some period of time after the original composition, they are seldom accurate or up to date.
Let's not forget that those books always say to get a permit with the local building department.
After seeing these comments I went back to check out the Rex Cauldwell book and it does explain the details of his "better" kitchen sink drain design. A picture might be worth a 1000 words, but sometimes you do need the words too!
To be fair, I will relate the following from the written text accompanying the picture:
1) he specifically addresses that although it may look like an s-trap in the photo, it is not. the angle of the photo foreshortens the appearance of the connector between the p-trap and the vertical drop making the pipe length look shorter than it actually is. the pipe is 1.5" and he used the rule of being 2x pipe diameter so the connector pipe is at least 3" and he says the true measure is to the trap weir which is obviously longer than the connector itself. so he says it is not an s-trap and in any case since he calls it out himself and explains it in the text it is quite clear what one needs to do to avoid an s-trap.
2) he also addresses the issue of venting. the text explains that this is a real-world example and in this particular remodel there was not a previously installed kitchen drain vent. he lists three alternatives to dealing with this: a) plumbing a thru-the-roof vent pipe, (which he dismisses as too expensive to retrofit--at least on the example job) b) using an AAV, (which he says he might add, I think it was to the top of the double-wye) and c) that if the pipe is sufficientally upsized it allows for airflow over the flood level within the pipe. he goes on to say that this is local-code dependent and may not fly elsewhere (but apparently is ok where this example was implemented). so venting is actually addressed in the text.) the pipe is upsized to 2" for the vertical and then it connects in to a vented 3" pipe.
Anyway, as a DIYer I found some useful stuff in his books; elsewhere I recommended a book by Peter Hemp as my favorite (so far). i think the key for DIYers is to get several books based on recommendations and then to go online and ask for clarifications. The help on this site and others like it is invaluable. Besides the UPC code, I have 6 or 7 different books that I reference.