The V30 looks like a full wave rectifier with its twin anodes. The data given for the V30, however, states that it is a half wave rectifier and therefore the anodes must be connected in parallel. As the valve has a 30 Volt 200 mA heater, and this is consistent with universal equipment without mains transformers this looks correct. The V30 was made as a replacement product and not for inclusion in new equipment.
The classic envelope is 36 mm in diameter and, excluding the B5 base pins, is 86 mm tall.
References: 1040 & 1043. Type V30 was first introduced in 1936.
Absolute Maximum Operating Conditions¶
Updated January 25, 2013.