Conventional Globe Valves may be used for isolation and throttling services. Although these Valves exhibit slightly higher pressure drops than straight=through Valves (e.g., gate, plug, ball, etc.), they may be used where the pressure drop through the Valves is not a controlling factor. [Because the entire system pressure exerted on the disc is transferred to the Valves stem, the practical size limit for these Valves is NPS 12 (DN 300). Globe Valves larger than NPS 12 (DN 300) are an exception rather than the rule. Larger Valves would require that gigantic forces be exerted on the stem to open or close the Valves under pressure. Globe Valves in sizes up to NPS 48 (DN 1200) have been manufactured and used.