Hello all,

I'm very new to Houdini and I am trying to simulate fluid flowing through a valve with a hinged disc in it. When the fluid enters the valve, it should push open the disc, allowing fluid in. The problem I am running into is that I can't seem to keep the disc hinged into position, it keeps breaking away.

I am using the RBD Hinge constraint with the hinge points set to the center of the pin the disc is hanging from, which is also the pivot point of the disc. I tried increasing the mass of the hinge, lowering the fluid output, but the disc still flies off. I need a way to keep the disc locked down to only rotation in the X direction, like a normal hinge would operate. As you can see in the attached image, this small amount of fluid has already de-hinged the disc.

I have attached a .zip file with the Houdini scene and imported geometry I am working with. Simulating up to frame 60 will show the problem. Any help would be appreciated. Thank you.