Rusty backflow assembly repair

This Wilkins 975 RPBA failed the annual backflow assembly test over a year ago. The backflow tester shut off the valves and the assembly was left to rust. The scale build up you see here is common in systems with high water demand. At some point someone had stripped out the relief valve clover bolts too, in an attempt to fix something that was not broke.

Regardless after extensive cleaning and new parts this backflow prevention assembly has passed the test and is back in service.