Spirax Sarco公司新型Spira-Trol通用辅助控制阀的突出特征是为精确操作而进行的全标准设计，在应用上它有着极大的可调范围，包括医药、橡胶、金属和化学。不论是ANSI还是EN型都有着形同的内部结构，而且阀门必需的三个气动执行装置在大小上可达4in。
在这一主体系列内有多种选择，包括低噪音和低流量应用甚至可以满足高温和零散发要求。
此款阀门拥有自我矫正系统和可固定位置的内部结构它坚固平滑的原料和标准设计使其从塞到底做更加灵活，减小内部流量速率，把内部损耗降到最低。
另外，阀门的可选择范围包括，电动、气动和调节执行器；外部控制系统界面；无接触远程调节器等。
Spira-Trol general service control valve
Spirax Sarco"s new Spira-Trol general service control valve features a fully modular design engineered for refined performance and wide rangeability in applications including pharmaceutical, rubber, metals, and chemicals.
Both ANSI and EN versions share the same internals, and three pneumatic actuators are required for valves up to 4in in size. There are many options within this one body envelope, from low noise and low flow applications, to high temperature and zero emission requirements. The valve incorporates self-aligning and clamp-in-place internals. Its hard trim materials and modular design diffuses the discharge from the plug and seat, as well as reduces internal flow velocities to minimize internal erosion.
Standard offering includes cast iron, SG iron, carbon steel, stainless steel or NACE construction; equal percentage, linear or fast-opening flow characteristic; 1/2- to 4in sizes with standard or customer-defined centre face dimensions; and ANSI, PN, JIS, KS, NPT, BSP, or SW connections. Additional valve options include electric, pneumatic, or modulating actuation; external control system interface; noncontact feedback positioners; PTFE chevron and graphite rings; and reduced flow characteristic.