SMSC 1SV — Single Cartridge Mechanical Seal ( Large 3″– 4″)

The SMSC 1SV Large is our single-cartridge seal for big-bore services (3″ to 4″). Assembled in-house from high-quality components sourced domestically and internationally, it delivers reliable, durable performance with service-friendly maintenance and strong value.

At a glance:

• Style: Single cartridge, stationary design (excellent for high speed)

• Sizes: 3″ to 4″

• Flush: 1 × 3/8″ NPT flush port standard for cooling and longer seal life

• Geometry: Short inboard axial length to simplify installs and reduce overhang

• Balance/Drive: Hydraulically balanced faces, positive set-screw drive, non-shaft-fretting sleeve elastomer

• Handling: Double-lip metal spacer clips for secure shipping and perfect fitment

Why it lasts:

• Monolithic seal faces maximize face stability in high-pressure/high-temperature duty, extending run time

• Large-area face drive minimizes damage in stop/start and viscous services

• Slotted anti-rotation gland with a wider, rounded slot improves durability under frequent cycling

• Multiple springs provide uniform face loading and superior axial movement compensation.

Typical uses:

Large-frame pumps in chemical processing, power, pulp & paper, water/wastewater, mining, and general industrial services—especially where HP/HT, viscosity, or frequent starts/stops are expected.

Need help sizing or selecting materials? Contact us with your pump model and service details—we’ll spec the best 1SV Large build for your duty.