in Flowserve
Flowserve E51/52 Flanged Ball Valve

Enviro-Safe High integrity

Size Range: The Enviro-Safe comes in 8 sizes ranging from ½” to 6” (15mm-150mm).With environmental protection and control established as a major issue for the future, Flowserve Worcester Controls provides a range of high integrity valves: the Enviro-Safe E51/52.Worcester’s primary aim was to design a range of Class 150/300 ball valves to prevent external leakage in demanding applications such as highly toxic media (phosgene, chlorine etc.) or with very costly media where wastage is unacceptableWorcester’s Enviro-Safe range of ball valves has a high cycle life at an increased range of temperatures and pressures. At the heart of the valve’s high integrity performance is its dual stem packing. The unique primary seal is designed so that it will always fail in service BEFORE the secondary seal. With a monitoring port drilled through to a lantern ring which is located between the two sealing stages, primary seal leakage can be detected whilst the secondary seals ensure overall integrity. This unique and foolproof stem packing design is live loaded with stainless steel disc springs and has been proven in testing to be bubble-tight on helium even after primary seal leakage. Primary seal integrity can then be restored by simply tightening down the gland plate.


The Enviro-Safe features two stem purge bosses. One is drilled and tapped to 1/8″ BSPT standard thread that allows connection of instrumentation/sensing devices, while the optional second port allows through purging between the stem seals. In addition the one piece body eliminates unnecessary joints.

The Enviro-Safe valves are also available in firesafe versions EF51/52 or sour gas versions to NACE (MR. 0175/ISO 15156).

A further benefit allows automated versions to have the actuator removed without affecting the integrity of the valve seals.


The 40R is A high performance actuator which combines reliability and long life and is based on the opposed double rack and pinion principle utilising piston support rods to minimise friction and wear between pistons and body bore.

There are twelve sizes of Norbro double acting or fail safe spring return pneumatic actuators providing a torque range of 11 to 4617 Nm (at an operating pressure of 5.5 bar). This enables efficient and therefore economical torque matching.

A wide range of ancillary equipment can be fitted to meet the most exacting customer requirements. This is an area where Flow Control Solutions Ltd and Worcester has considerable experience and we would be pleased to discuss any process problems. Since the mid-Sixties the Norbro name has been recognised as the leading quarter turn actuator for industry. As proof of this, Norbro pneumatic actuators can be found in a range of applications as diverse as the petrochemical industry, food and beverage, steel production, pharmaceuticals and plastics manufacturing