Which component consists of inlet and outlet isolation valves, a bypass valve, and a pneumatically operated pressure-regulating valve?

• A. Gland seal regulating station
• B. Unloading valve
• C. Bypass valve
• D. Make-up valve

Answer: (A)

Regulating gland seal pressure requires a compact control assembly that can isolate, bypass, and automatically regulate the steam applied to the stuffing box. The gland seal regulating station does exactly this: two isolation valves to shut the station off for maintenance, a bypass valve to allow steam to bypass the regulator when needed (such as during start‑up or regulator fault conditions), and a pneumatically operated pressure-regulating valve that modulates the gland steam flow to maintain the desired, stable pressure at the gland. This setup keeps a small, positive pressure around the shaft packing, preventing air ingress and reducing seal wear. The other options don’t describe this complete control assembly: an unloading valve is just a valve used to shed load, a bypass valve alone isn’t a full regulating station, and a make-up valve relates to feedwater or steam makeup rather than gland sealing.