Single vs. Dual Cartridge Seals: Which One Do You Need?
One of the most common questions pump operators face is whether to install a single cartridge seal or upgrade to a dual cartridge seal. Both options are engineered for reliability, but each serves a different purpose depending on your operating conditions. This guide will help you decide which is right for your pump.
What Is a Single Cartridge Seal?
A single cartridge seal has one sealing interface (the faces). It’s compact, easy to install, and often the most cost-effective solution.
Best for:
General-purpose pumping
Clean liquids
Applications with low to moderate pressure
Users who prioritize simplified installation and affordability
Paradigm Example: A1 Single Cartridge Seal (available in SC/CAR or SC/SC faces).
What Is a Dual Cartridge Seal?
A dual cartridge seal has two sets of sealing faces, creating an inboard and outboard seal. These seals are designed for more demanding environments where leakage control and safety are critical.
Best for:
Hazardous or abrasive fluids
Applications requiring environmental containment
High-pressure or high-temperature operations
Pumps in industries like chemical processing or refining
Paradigm Example: A2 Dual Cartridge Seal (available in SC/SC/SC/CAR or SC/SC/SC/SC faces).
Pros and Cons at a Glance
Single Cartridge Seal
✔ Easier to install
✔ Lower cost
✔ Ideal for standard pumps
✘ Limited in harsh or hazardous applications
Dual Cartridge Seal
✔ Enhanced leakage control
✔ Greater reliability in tough conditions
✔ Suitable for safety-critical pumps
✘ More expensive
✘ Slightly more complex installation
How to Decide
Ask these questions before choosing:
What liquid am I pumping? (Clean water vs. chemical slurry)
What’s the operating pressure and temperature?
Is environmental containment required by regulation or safety policy?
What is the cost of downtime if the seal fails?
Paradigm’s Approach
At Paradigm Seals™, we offer both A1 Single and A2 Dual Cartridge Seals so you can match your seal to your exact operating conditions. Not sure which is right? Use our Find Your Seal Form or contact our team for expert guidance.
Key Takeaway
Choose a single cartridge seal for clean, general-purpose applications. Choose a dual cartridge seal for harsh, hazardous, or highly regulated environments.
