Mechanical Seal FAQ

A mechanical seal is the component that prevents pumped media from leaking out where the pump shaft passes through the casing. Two precision-lapped faces — one rotating with the shaft, one stationary — ride on a microscopic fluid film, sealing while allowing rotation.

Typically 3-10 years depending on duty, media and installation quality. Water quality, abrasives, cavitation and dry running are the main life-shorteners. Mechanical seals are wear parts — replacement is normal maintenance, and we say so honestly.

Send us your pump brand/model, shaft diameter, seal bore (or old seal part number), media, temperature and pressure. We cross-reference standard seal sizes and confirm the fit before you order.

Single seals have one sealing face pair — the standard for clean duties. Double seals have two pairs with barrier fluid between — for hazardous, toxic or abrasive media. Cartridge seals are pre-assembled units that install without measuring, cutting downtime dramatically.

Common face materials: silicon carbide (SiC), tungsten carbide (TC), ceramic and carbon. SiC/SiC is the default for water and most chemicals; TC handles abrasives; ceramic/carbon is cost-effective for clean light duty. We match the material to your media.

The seven most common causes: wrong seal selection, installation damage, shaft runout, cavitation, dry running, wrong spring setting, and worn faces. Our guide covers how to diagnose each — see Mechanical Seal Leaking: 7 Causes & Fixes.

Yes. Sample orders of 1-10 pieces are welcome at factory-direct prices, so you can verify fit and quality before committing to volume.

Standard replacement sizes ship in 7-15 days. Custom or non-standard sizes are quoted individually after drawing or sample confirmation.

No hard MOQ for standard replacement seals — one piece is fine. Custom/OEM production MOQ depends on size and complexity, quoted honestly per project.

Yes — installation instructions, videos and engineering support by email/WhatsApp are included with every order.

Yes — custom sizes, materials and designs from drawing or sample, with OEM/ODM production and QC documentation on request.

Yes. Send the old seal (or accurate measurements plus photos) and we identify the configuration, materials and dimensions, then produce matching or improved seals.

T/T bank transfer for standard orders; other arrangements discussed for larger or repeat business.

Yes — we ship to distributors, MRO teams and pump service companies worldwide, with export documentation arranged on request.

Pump brand/model, shaft diameter, bore size, media, temperature, pressure, quantity, and a photo of the old seal if available. The more you provide, the faster we confirm.