In the illustrated self-contained, internal-pilot, piston-operated temperature control valve, what statement is true concerning the pilot and main valves? GS-0045

Correct Answer: Option B — The pilot valve is upward seating and the main valve is upward seating.

In this specific internal-pilot design, both the pilot valve and the main valve are configured as upward-seating. This arrangement ensures that the steam pressure acts against the valve discs to assist in the closing action, which is a standard design feature for this type of temperature control valve.