Antique single check valve backflow device

Here we have a weighted/swing check single check valve backflow prevention device. This device is not testable. I’ve taken the liberty of attempting to group all the internal parts together to give you a general idea of its design.

From lower left to right, check valve weight, the check valve, weight & check valve brackets, retainers, & pins, and 8 cover bolts.

Click on photo to enlarge.