THE STORY OF DURAMAX CHAIN

DuraMax Cast Stainless Steel Chains: Lower Maintenance, Longer Life

Key advantages: corrosion + abrasion resistance with high strength—built to maximize uptime and reduce total cost of ownership in water/wastewater and other severe-duty applications.

Patents: US 7,237,375 B2; US 7,343,730 B2; Canadian Patent 2,519,653

A brief evolution (why the design changed)

In water and wastewater equipment, traditional cast steel chain became the go-to solution because it was robust and cost-effective. Over time, however, operators in more aggressive environments saw that corrosion and abrasion could quickly accelerate wear—often driving major repair or replacement within 3–5 years in many applications.

That led to a series of design tradeoffs: plastic chains reduced corrosion-related wear but introduced limits in strength and run length (often around ~250 ft in common collector applications) and could struggle in sustained abrasive service. Fabricated and welded stainless options improved corrosion resistance, but many designs gave up working load and abrasion performance (with some fabricated “715” designs providing about 2/3 of cast steel ultimate strength and <50% of cast steel working load). DuraMax cast stainless steel chain represents the next step in that evolution—aimed at combining corrosion resistance and abrasion resistance with high capacity to reduce maintenance and extend service life.

Key facts (maintenance & longevity)

  • Cast steel chains (700 Series, H-series): widely used in clarifiers, collectors, grit handling, and screening equipment, but wear accelerates in corrosive/abrasive service.
  • Primary wear drivers: corrosion-erosion and corrosion-abrasion (often the majority of wear), plus sprocket tooth contact that removes protective oxide layers.
  • Typical service life in many water/wastewater applications: 3–5 years or less before major repair/replacement.

Where alternatives fall short (maintenance impacts)

  • Plastic (acetal) chains: reduce corrosion-related wear but trade off strength/working load. 
    • Common application limit: 720S plastic often limited to ~250 ft collector runs; abrasion resistance can be limiting in sustained cross-collector service.
    • Maintenance/outage risks: UV exposure, cold-temperature brittleness, ice/frost buildup, and thermal expansion/contraction can contribute to tension issues and operational variability.
    • Abrasive service fit: generally not suited for sustained headworks/grit/sand environments where abrasion and high loads can drive premature failure.
  • Fabricated stainless (often 400 series): may offer improved corrosion resistance versus steel, but can still be vulnerable to chloride embrittlement, stress-corrosion cracking, and chemical attack in common water/wastewater chemistries (e.g., chlorides, sulfides, hydrogen sulfide, ammonia).
    • Capacity limits: many fabricated “715” designs provide about 2/3 of cast steel ultimate strength and <50% of cast steel working load, which can increase overload/outage risk in demanding service.
  • Welded stainless (often 304): good corrosion resistance but relatively soft with limited abrasion resistance; weld areas can become embrittled and reduce strength/working load over time.
    • Total lifecycle impact: labor-intensive fabrication and cost-driven design compromises (smaller pins/thinner sidebars/lower-cost materials) can shorten service life and increase maintenance frequency.

DuraMax: maintenance reduction + long service life

  • Material + process: precision-cast stainless alloys into high-strength CS720S, CS715SS, H82, H7124 links (unitized one-piece castings; not assembled from stamped parts).
  • Corrosion resistance: excellent resistance (approaching 316 stainless steel) for severe-duty corrosive environments.
  • Abrasion performance: hardness greater than chilled cast iron to help resist wear in abrasive services.
  • High capacity: engineered to avoid the strength/working-load constraints common to plastic and many fabricated stainless designs.
  • Faster maintenance: links can be assembled by one person by hand (no hammers or clamping tools required).

Best-fit applications: stormwater/headworks and severe-duty water & wastewater equipment (bar/catenary screens, trash rakes, grit collectors, chain-and-flight collectors and cross collectors, paddle-wheel and turbine flocculators), plus industrial conveying/power transmission where corrosion and abrasion drive maintenance.

Chemical/biological resistance: withstands acids, alkalis, hydroxides, sodium and calcium chlorides, sulfide compounds, and gases such as hydrogen sulfide and ammonia—supporting longer wear life in common treatment-process environments.

Reduced maintenance: longer wear life can decrease the frequency of tensioning, chain/sprocket repair, and replacement—helping avoid repeated tank/basin shutdowns, draining, and cleaning.

Sustainability: uses up to 25% post-consumer recycled material; cast stainless alloys are fully recyclable at end of life and long service life reduces replacement waste.

Standards: CS720S/730 and CS715SS meet or exceed ASME B29.21M-1996/2003; H78/988 and H82/C9103 meet or exceed ASME B29.11M and B29.14M-2008.

Longevity & warranty: designed to reduce total cost of ownership; in many applications, DuraMax Chains and DuraMax Sprockets can deliver up to 20 years of 24/7/365 continuous-duty service without repair or replacement, backed by a standard 10-year Full Replacement Warranty.