On reflection they might have just googled "steam safety valve" and copied the first image they saw, they probably didn't need an expert involved. They hadn't

On reflection they might have just googled "steam safety valve" and copied the first image they saw, they probably didn't need an expert involved. They hadn't insulated their piping, which would have led to condensate forming in deadlegs and causing steamhammer issues, but to be fair I don't believe the Mario Bros had designed or installed this system, and it was exploding at the time.