Material Selection for Chemical Process Equipment – Overview
Is your surface finishing line well-designed? Material selection for chemical process equipment is critical to the design and implementation of high-quality and cost-effective surface finishing systems. The goal of this seven-part series is to discuss some basic information to help identify and plan for the complex array of design and life cycle project considerations for material selection for process systems. This series will lay out the major material groupings; discuss the factors that impact material selection in practical application; and, finally, tie everything together by exploring the economic and operational benefits of proper material selection. To kickoff, the following is an overview of the topic of material selection for chemical process equipment.
Overview
Whether planning new or renovated wet process systems, material selection for chemical process equipment should be carefully evaluated and documented for all process systems that will or could be exposed to the planned process chemistries. Critical systems to consider include, but not limited to:
Primary and ancillary process systems/equipment, and all subcomponents, that store, transfer, or process the wet process fluids, including fluid tanks and attachments, pumps, piping/valving systems, filters, heat exchangers, treatment vessels and reactors, and sumps.
Hoists, cranes, and transport systems.
Exhaust ventilation collection and air pollution control systems.
Exteriors of process systems/equipment, and all subcomponents, as well as all related/other systems and structures (e.g. – grating, platforms, ladders) that will be or potentially could be exposed to spills, splashes, or vapors from the process fluids and associated process chemistries.
Electrodes, eductors, sensors, fixtures, and other devices immersed in process solutions.
Instrumentation and control systems, including panel enclosures.
Conduit and enclosures for electrical power and distribution systems.
Spill containment systems and wastewater treatment systems.
For each application, a full material selection must include all components, including wetted and non-wetted surfaces, motors, gaskets and seals, miscellaneous mechanical, electrical, and I&C devices and parts/components. Material selection for chemical process equipment impacts systems designed and selected across process, mechanical, electrical, I&C, civil, and architectural disciplines.
About Material Selection
Complete material selection for even a single piece of equipment, like a process solution pump, can include a combination of several materials needed to provide long life for all subcomponents. Commercial material variations in purities, compositions, densities, and other properties are available for different applications and can provide varying chemical resistance and different physical properties. Even though some materials have generally superior chemical resistance across a range of chemistries, there are specific chemistries and applications where a typically superior, higher cost material will underperform a lower cost material with typically lower resistance to chemical attack. Chemical resistance can be highly application-specific and must be carefully evaluated.
Next week, watch for Part 1: Material Selection for Chemical Process Equipment – Metals. Part 1 provides information on steel and stainless steels (e.g. 304LSS & 316SS), copper, zinc, and nickel, high content nickel alloys like Hastelloy C-type, high performance metals like titanium, tantalum and zirconium, and selected uses of precious metals like silver, gold, and platinum.