With over 35 years of installation history, the Masoneilan 74000 series valves serve a unique role in advanced oil refining operations. One leading-edge refining process is known as Residual Hydrocracking. Positioned downstream of the vacuum unit, this process converts “bottom-of-the-barrel” residuals through a reactor to produce high value mid-distillates such as diesel. This fluid is laden with point-of-origin contaminants and particulate matter, and when combined with abrasive catalysts can destroy conventional control valves in a matter of days, or even worse. This is where the 74000 shines.
The 74000 series is the next tier in severe service that takes over in extremely erosive applications where traditional high-pressure reduction, severe service refining products like the Masoneilan LincolnLog and 77003 series become limited due to the erosive flow characteristic.
Unique Severe Service Design
Residual Hydrocracking introduces process attributes that require valve features that can hold up under a combined load of pressure and temperature with entrained solids yielding severe erosion. Some of these valve applications are so erosive that conventional trim staging is not effective, and is in-fact self-limiting.
Concentration of Entrained Solids and Process Catalysts
The 74000 design counters this with ample transition areas and flow path management to reduce body impingement.
High Pressure Drop
These can be so severe and at such high velocity that the confined spaces and convoluted geometry of multi-staging can be ineffective, even destructive as the high velocity flow impinges on trim and body surfaces. The 74000 employs a rugged single-stage design with minimal internal impingement, leading to simple flow lines and managed velocity.
High Velocity Erosive Flow
The 74000 employs a unique tungsten carbide surface treatment on the plug and seat ring and includes a sacrificial ceramic venturi tube below the seat where velocity is the highest and most destructive.
To deal with process fluid changing state from liquid to gas as a result of the severe pressure drop, the 74000 has an integral expanded outlet to manage downstream velocity. Bear in mind that the solids are present in the valve outlet flow, and with increased outlet velocity due to outgassing, severe erosion is present and destructive.
Longer Intervals Between Maintenance
Refinery units typically target turnaround intervals in the range of around 3 years. In many cases, inferior control valves are driving dramatically shorter intervals measured in months rather than years. The 74000 has proven considerably longer cycles, in many cases matching targets of 3+ years, with some applications even doubling those intervals.