Chemical processing plants handle some of the most aggressive fluids any rotating equipment ever sees — concentrated acids, caustics, solvents, and reactive intermediates that will attack a mismatched seal face, elastomer, or metallurgy within weeks rather than years. A mechanical seal chosen without full regard for the specific chemistry it will contact is one of the most common and most expensive failure points in a chemical plant, driving unplanned shutdowns, product loss, and in the worst cases, hazardous releases.
At Leak-Pack Engineering, we design and manufacture mechanical seals for chemical process equipment — reactors, agitated vessels, transfer pumps, and centrifuges — engineered around the specific chemical compatibility, temperature, and hazard classification of your process. Our engineering team works from your fluid’s material safety data and process conditions, not a generic “chemical duty” catalogue listing, to recommend seal face materials, secondary seals, and metallurgy that will actually hold up in service.
In most industries, seal selection starts with pressure and temperature. In chemical processing, it starts with chemical compatibility, because the wrong elastomer or metallurgy can fail within days regardless of how well the mechanical design otherwise fits the application. A seal face or O-ring that performs perfectly in one chemical family can swell, crack, or corrode rapidly in another — concentrated sulfuric acid, for instance, calls for entirely different secondary seal and metallurgy choices than a chlorinated solvent, even though both are common in the same plant.
This is also where regulatory exposure enters seal selection. Facilities handling threshold quantities of hazardous chemicals fall under EPA Risk Management Program requirements, which puts direct scrutiny on accidental release prevention — and an under-specified mechanical seal on a covered process is a release pathway regulators, insurers, and plant safety teams all treat seriously. We build compatibility and containment into the seal specification from the outset rather than defaulting to a standard elastomer and hoping it holds.
Getting this wrong is expensive in a specific way: a seal that fails from chemical attack often looks, on the surface, like a mechanical or installation failure, so plants sometimes replace several seals on the same duty before anyone traces the root cause back to a material compatibility mismatch. We start every chemical-service quote with the fluid data sheet specifically to avoid that cycle.
Chemical plants run a wide mix of batch and continuous equipment, each presenting a different combination of chemical exposure, temperature, and mechanical duty. We supply seals across this full range:
As in other heavy process industries, these rarely present in isolation — a seal on an acid transfer pump usually has to resist chemical attack, contain a hazardous fluid, and tolerate some process variability all at once. We size the specification to all three simultaneously rather than optimizing for one and hoping the others hold.
Below is a general guide to the materials we typically recommend by chemical application. Final material selection is always confirmed against your specific fluid concentration, temperature, and any cyclical process conditions — chemical compatibility in this industry is too fluid-specific for a one-size guide to be the final word.
| Application | Seal Face Combination | Secondary Seal / Elastomer | Wetted Metallurgy |
|---|---|---|---|
| General acid/caustic transfer | Silicon Carbide vs. Silicon Carbide | FFKM (Kalrez-type) | Hastelloy C / 316 SS |
| Strong acids (sulfuric, nitric) | Silicon Carbide vs. Silicon Carbide | PTFE (elastomer-free) | Alloy 20 / Hastelloy |
| Solvent & aromatic hydrocarbon service | Silicon Carbide vs. Silicon Carbide | FFKM (Kalrez-type) | 316 Stainless Steel |
| Slurry / crystallizing media | Tungsten Carbide vs. Silicon Carbide | FKM / EPDM | 316 SS / Duplex |
| High-temp reactor service | Silicon Carbide vs. Silicon Carbide | PTFE / Metal bellow (no elastomer) | Hastelloy / 316 SS |
We start from your fluid’s material safety data sheet — chemical composition, concentration, and operating temperature — and select seal face, secondary seal, and metallurgy combinations validated for that specific chemistry, rather than defaulting to a generic chemical-duty seal.
Yes. We specify elastomer-free PTFE or metal bellow designs with acid-resistant metallurgy such as Alloy 20 or Hastelloy for strong acid transfer and process applications.
Yes. Our PTFE / Teflon Bellow and Metal Bellow Mechanical Seals remove the dynamic elastomer entirely, for solvent and aromatic hydrocarbon services where standard O-ring compounds degrade over time.
Yes. Our agitator and reactor seal designs are engineered for variable-duty batch cycles, and we review the full batch sequence — not just the primary process fluid — when specifying materials, including any cleaning or purge chemicals the seal will contact between batches.
Yes. We engineer barrier and buffer fluid support systems sized to the specific chemical being contained, for applications where any atmospheric release is unacceptable.
Yes. We specify hard-face combinations, typically tungsten carbide or silicon carbide pairings, selected for resistance to abrasive wear from suspended solids in slurry and crystallizing service.
Lead times depend on seal size, material availability, and arrangement complexity. For standard cartridge and split seal replacements in common chemical services, we prioritize fast turnaround to minimize batch and production loss — share your seal drawing or process details with our team for a firm timeline.
Yes. Our cartridge and split seal designs are engineered for retrofit onto most existing chemical process equipment, including as upgrades from seals that have failed due to chemical incompatibility.
Chemical compatibility is too fluid-specific for a generic catalogue seal to reliably get right, which is why every seal we quote for this industry starts with your actual process fluid data, not a standard “chemical duty” listing. We’re happy to work alongside your process safety and reliability teams where a seal specification needs to support broader chemical accident prevention documentation.
Send us your reactor, vessel, or pump specifications — fluid composition, concentration, and operating conditions — and our engineering team will recommend the right seal solution for your application. Explore our full range of mechanical seals by industry or send an enquiry directly.
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