The existing 1” NB Stainless Steel ‘Flowstream’ Globe / Plug Type Pneumatically Actuated Valves were obsolete and nothing similar was available from alternative manufacturers. The space envelope these valves / actuators fit into was fairly limited, and the face to face dimension of any replacement had to be identical as pipework modifications would be difficult due to their location within gloveboxes. In addition these valves were being used on HP Steam Lines which are rated 330˚C at 11.5 BarG.
NW Total sourced some ST/ST Ball Valves with Metal Seats suitable for use on temperatures up to 500˚C. The ¾” NB Class 300 version of this valve was used as the face to face was almost identical to the existing valves, plus the full bore design overcame the need for a 1” valve. NW Total manufactured special weldneck flanges to convert this valve to 1” BS10 Table ‘H’ and also match the exact required face to face dimension. In addition a standard actuator could not be used due to space constraints, so a Compact II Actuator was used which has a square shape instead of rectangular. After assembly these valves were pressure and function tested to check the Actuator operation at NW Total’s premises, and after installation were found to operate to satisfaction.