Spirax BSA3 Bellows Sealed Steam Valves is a low maintenance flanged in-line Bellows Sealed Isolation Valve for use on steam, condensate, gas and other fluid applications where zero emissions from the stem seal are important. BSA3T is fitted with a throttling valve plug that allows close control when opening the valve. Locking screw and stroke limiter maintains correct flow rate once the flow rate is obtained. The “T” version is to be used for regulating duties.