High Rangeability Applications
All control valves have an inherent flow characteristic that defines the relationship between ‘valve opening’ and flowrate under constant pressure conditions. Please note that ‘valve opening’ in this context refers to the relative position of the valve plug to its closed position against the valve seat. It does not refer to the orifice pass area. The orifice pass area is sometimes called the ‘valve throat’ and is the narrowest point between the valve plug and seat through which the fluid passes at any given time. For any valve, however it is characterised, the relationship between flowrate and orifice pass area is always directly proportional.
Valves of any size or inherent flow characteristic which are subjected to the same volumetric flowrate and differential pressure will have exactly the same orifice pass area. However, different valve characteristics will give different ‘valve openings’ for the same pass area. The physical shape of the plug head and seat arrangement, together also referred to as the valve ‘trim’, causes the difference in valve opening between these valves.
MTECK has the engineering capability to design and manufacture High Rangeability trims for a wide variety of applications both in liquid and gas services.
