FPD220 Dual-Chamber Orifice Fitting Operating Instructions

This document provides installation, operation, and maintenance procedures for the ABB FPD220 dual-chamber orifice fitting, which is designed for safely inspecting and changing orifice plates while the line remains pressurized. It emphasizes safety compliance with HSG253 guidelines for "Category II Proved Isolation," using pressure gauges to monitor chamber pressures before plate removal.