Since the first concept for a LEGO auto-valve by Sariel, there have been several other variants with their pros and cons.
One that I most liked, despite the strange look and unconventional use of this part (61904), was the design proposed by Sardo.
This idea was discussed at SeTechnic forum while ago, and soon some other "optimized" designs came-up.
It might become useful somewhere!
Please avoid sending requests to post specific models on this TBs section.
We understand some of you would enjoy to see your creations featured here, but please understand that because only one video gets highlighted per week, it is impossible to accommodate all the great MOCs continuously build by the Technic builders out there. They simply won't fit all and that's also not the purpose of this blog (see the header statement).
Many of your MOCs are scanned anyway and listed for later publication when they do not fit immediately. However some remain in the backlog queue just for too long and eventually loose the relevance or the publication opportunity window. As a rule of thumb, we also avoid publishing MOCs that have been featured by their authors or other fans at some other great web places dedicated to the Technic community out there. It doesn't mean that occasionally some won't get published here anyway.
Thanks for your understanding!