Does the double eccentric butterfly valve have a pinless design?

If you’ve ever come across a butterfly valve that claims to be “pinless” – especially in double or triple eccentric designs – let’s clear up the confusion once and for all.

The short answer: No, not really.

Both double eccentric and triple eccentric butterfly valves do have pins. Those pins are essential – they fix the disc to the shaft and ensure proper torque transmission and alignment during operation. Without them, the disc would not be securely fastened, and the valve could fail under pressure or cycling.

So why do some products look like they have no pins?

Here’s the trick: what you might have seen as a “pinless” valve is actually a valve where the pins were installed first, and then the exposed ends were ground down flush with the surface. After machining and painting, the pin holes become nearly invisible – but they are still there, doing their job inside.

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