clapet anti-retour de freinage

16:55 Dec 6, 2016 

NB the "equivalent circuit" diagram should not be taken too literally: the bleed path shown at the side need not necessarily be physically at one side. Engineering is full of equivalent circuits that represent physical reality but, more importantly, are amenable to modelling using elementary mathematical constructs.

16:47 Dec 6, 2016 

In addition to the symbol, there's a simple diagram: the check valve with its perforation (throttle) is in its seat; fluid flowing one way pushes it out of its seat, fluid flowing the other way pushes it into its seat. Normally this would close the valve but thanks to the perforation, a small flow is allowed in the other direction.
The diagram is similar to the one here:
http://valveproducts.net/check-valve/operation-principle-of-...
except of course for the throttle, which indeed has a "braking" effect on the reverse flow.
Chris, yes, the valve in the diagram in your link with the parallel small bore at the side certainly has the same function.

16:14 Dec 6, 2016 

It sounds like a one-way check valve or non-return check valve.

15:35 Dec 6, 2016 

Quite so - a check valve in parallel with a throttle. Your symbol, C-A, may be non-standard!

15:30 Dec 6, 2016 

The symbol does not match though. This is a throttle check valve symbol.
http://www.dr-breit.de/product/throttle_check_valve/throttle...

15:13 Dec 6, 2016 

It does sound like a throttle(d) check valve, though these are frequently represented schematically as a perfect check valve in parallel with a sometimes variable hydraulic shunt: http://www.kanflu.com/assets/PDFs/re275262008-04-Z2FS-16.pdf... Although your particular one has a hole down the middle (the gicleur) its "equivalent circuit" can still be represented as above and its effect is the same.

14:42 Dec 6, 2016 

I don't have any links to the symbol in my text, but it's exactly the same as this:
https://upload.wikimedia.org/wikipedia/commons/4/44/Symbol_C...
except that the centre of the ball is traversed by two parallel lines (apple after having the core removed with an apple corer).

14:37 Dec 6, 2016 

I have a suspicion what it is, but first I would like to see the symbol.
claude-andrew, can you post a link to a symbol of that valve?