They're not interchangeable — the symbol tells the reader the valve's function, which drives maintenance and operating expectations.
The plain bow-tie (two solid triangles meeting at a point) is the generic gate valve. Gate valves are for isolation: fully open or fully closed. They have low pressure drop when open but throttle badly and wear if you park them half-open. Use the gate symbol on block/isolation service where the valve is normally hard open or hard shut.
The bow-tie with a filled circle at the seat is the globe valve. Globe valves are built for throttling and modulating flow: good control resolution, higher pressure drop by design. Use the globe symbol on regulating/control service and on manual throttling points. Most control valves (with an actuator on top) are drawn on a globe body for this reason.
So the rule of thumb: isolation line -> gate; anything you intend to regulate -> globe. Getting the body right also tells the next engineer why the dP across that valve is high on purpose. More valve bodies and actuator conventions here: /learn/valve-symbols.html
The plain bow-tie (two solid triangles meeting at a point) is the generic gate valve. Gate valves are for isolation: fully open or fully closed. They have low pressure drop when open but throttle badly and wear if you park them half-open. Use the gate symbol on block/isolation service where the valve is normally hard open or hard shut.
The bow-tie with a filled circle at the seat is the globe valve. Globe valves are built for throttling and modulating flow: good control resolution, higher pressure drop by design. Use the globe symbol on regulating/control service and on manual throttling points. Most control valves (with an actuator on top) are drawn on a globe body for this reason.
So the rule of thumb: isolation line -> gate; anything you intend to regulate -> globe. Getting the body right also tells the next engineer why the dP across that valve is high on purpose. More valve bodies and actuator conventions here: /learn/valve-symbols.html