In a flash letdown system assembly, the valve mounting flange interfaces between the valve and blast tube. The entire unit is assembled to the flash vessel at the designated nozzle, typically at the top of the flash vessel. The thickness of the valve mounting flange is critical when mounted between a valve and a blast tube. If it is too thin, the valve seat will fit incorrectly into the blast tube, causing stack-up height issues for the entire flash letdown system. If it is too thick, there will be a gap between the valve seat outlet and inlet to the blast tube, creating undesirable flow characteristics of the flashing flow that can cause damage. The valve mounting flange also provides a structural interface between the valve assembly and the flash vessel, ensuring a secure and properly aligned connection.

Valve Mounting Flange Materials

Smaller valve mounting flanges are often made from solid corrosion-resistant materials like titanium or super duplex stainless steel. For larger flanges, cladding a carbon steel flange with corrosion-resistant materials is a common method for achieving the needed corrosion barrier. Cladding is typically done with either a mechanical or an explosion bond interface.