Abstract: The invention relates to fluid flow separators for use with high velocity production fluid flow. The separator has an expansion chamber provided with a flow barrier mounted within the chamber. The barrier is formed from an impact deformable material, such as wood, which allows the solid particles carried by the fluid flow to embed themselves and form a layer against which other solid particles strike without destroying the equipment. A choke assembly is mounted upstream from the barrier and is formed by a main body and a removable choke bean. The bean is threadably engaged within the main body to allow its easy removal once excessive wear is detected. A flexible O-ring seal is made upstream from the threadable engagement and another seal, metal-to-metal, is formed downstream from the engaging threads. A transverse port made in the main body communicates with an annular space formed between an interior wall of the main body and exterior wall of the insert downstream from the metal-to-metal seal.