Single cartridge mechanical seal
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Single cartridge mechanical seal

High-reliability single cartridge mechanical seal for industrial pumps — fast install cartridge design, API-682 compatible options, shaft range 25–127 mm (1.0–5.0″), pressure rating up to 25 bar. Ideal for chemical, petrochemical, water and process industries.

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Single Cartridge Mechanical Seal — Overview

A single cartridge mechanical seal (also known as cartridge seal, single seal cartridge, or cartridge mechanical seal) integrates the seal faces, gland, sleeve and springs into a single assembly for safer, faster installation and improved reliability. Cartridge seals eliminate complex field adjustments, reduce installation errors and minimize pump downtime — critical for continuous industrial processes.

Key selling points: quick retrofit for standard pumps, API-682 plan compatibility, multiple face & elastomer materials for corrosive/abrasive services.

Why choose a cartridge (single) mechanical seal?

Reduced downtime & error-free installation

Cartridge design comes pre-assembled and pre-set; install on the pump shaft without complicated face spring pre-loading — reduces technician time and risk of misalignment.

Broad operating envelope (typical)

  • Shaft diameter range: 25 mm to 127 mm (1.000″ – 5.000″) — standard stock sizes in 3 mm / 1/8″ increments; larger sizes available as engineered items.

  • Pressure: typical ratings up to 25 bar (363 psi) for standard single seals; engineered high-pressure cartridge variants exist (industry examples up to 40+ bar for specialized designs).

  • Temperature range: –40 °C to +220 °C depending on elastomer and face selection.

  • Peripheral shaft speed: Typical max sliding velocity 10–22 m/s depending on face materials and cooling plans (e.g., 16 m/s common for SiC/SiC combos; 22 m/s shown by some designs).

Note: stated extremes (pressure / temperature / speed) are independent limits — actual permissible combinations depend on face material, elastomer, balance design and flush plan.

Detailed product description

Our Single Cartridge Mechanical Seal is a balanced, single-acting seal available in single-spring, multi-spring or pusher cartridge formats. The stationary and rotary face pairs are offered in multiple commercial combinations (carbon vs ceramic, silicon carbide vs silicon carbide, metal-bonded carbide options) and the metallic parts are standard 316L/1.4404 stainless steel with optional Hastelloy C-276 or duplex for aggressive media and higher corrosion resistance. Typical elastomers: NBR (Nitrile), FKM (Viton), EPDM, and FFKM (perfluoroelastomer) for high temperature/chemical resistance.

Standard configurations available

  • Single stationary cartridge (standard) — economical, widely used for water, light chemical services.

  • API-compliant cartridge (API 682) — upgraded seal face/pusher design, compatible with API piping plans and qualification testing.

  • High-pressure cartridge — reinforced components and special face grades for pressures above standard ranges.

Applications (where this product fits)Single cartridge mechanical seal

  • Centrifugal pumps in chemical & petrochemical plants

  • Boiler feed & condensate systems

  • Cooling water / HVAC pumps

  • Municipal water & wastewater treatment pumps

  • Pulp & paper process pumps

  • Food & beverage (sanitary variants available)

  • Mining & slurry (with hardened faces and flush plans)

Technical specifications (typical / stock range)

The table below shows the standard, ready-to-stock ranges for our single cartridge mechanical seals. For specific pump models, API plan, or non-standard sizes please request a custom quote.

Parameter Typical value / range
Shaft diameter (d1) 25 mm – 127 mm (1.000″ – 5.000″) (stock in 3 mm / 1/8″ increments).
Pressure rating Up to 25 bar (363 psi) for standard designs; higher-pressure cartridges available.
Temperature range –40 °C to +220 °C (depends on elastomer/face selection).
Sliding velocity (vg) 10–22 m/s (dependent on face combo and flush/cooling plan).
Face material options Carbon / Ceramic, Silicon Carbide (reaction-bonded/sintered), Tungsten Carbide.
Elastomers NBR, FKM (Viton®), EPDM, FFKM (Kalrez®) — select per media compatibility.
Metal parts 316L (1.4404) standard; Hastelloy C-276, Alloy 20, Duplex on request.
Balance type Balanced (standard) / Unbalanced (special cases)
Connections API piping plans compatible (01/02/11/31/32 etc.) for API variants.

Common standard sizes & ordering codes

Common shaft sizes (stock): 25 mm, 28 mm, 30 mm, 32 mm, 35 mm, 38 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, 105 mm, 110 mm, 115 mm, 120 mm, 125 mm, 127 mm.

Example ordering code format (sample):
SC-25-SS-CC-FKM = Single Cartridge (SC), 25 mm shaft, Stainless Steel body (SS), Carbon/Carbon faces (CC), Elastomer FKM.

Advantages — why buy this seal

  • Quick drop-in retrofit for common pump frames — lowers downtime and service costs.

  • Pre-set cartridge reduces field errors and guarantees face concentricity.

  • Multiple certified options — API-ready configurations available for hazardous services.

  • Wide material selection for corrosive, abrasive and high-temperature services (SiC, WC, Carbon, FFKM).

  • Engineered cooling/flush plans compatible with common API plans to manage heat & solids.

Face & material selection — quick guide

  • Carbon vs Silicon Carbide: carbon offers better conformity and dry-run tolerance; silicon carbide provides superior hardness, wear and chemical resistance — choose SiC for abrasive or highly corrosive services.

  • Ceramic: cost-effective, wear resistant in clean services; avoid where thermal shock or heavy vibration expected.

  • Elastomer choice: use NBR for hydrocarbons and standard temps; FKM for higher temp/chemical resistance; EPDM for hot water/steam; FFKM for aggressive chemistries.

Comparison table — face materials (quick reference)

Property Carbon Ceramic Silicon Carbide (SiC)
Hardness Low–Medium High Very high
Abrasion resistance Low Medium–High Very high
Chemical resistance Good (organics) Good Excellent
Dry-run tolerance Better than ceramic Poor Poor–medium
Typical cost Low Medium High
Best for Dry run, sealing on rough surfaces Clean water, HVAC Abrasive/chemical, long life

FAQ

Q1: What information do you need to quote a cartridge seal?
A: Pump make/model, shaft diameter, shaft runout, operating pressure & temp, pumped fluid, desired piping plan (API Plan if any), material compatibility requirements. Providing a pump tag number or OEM model speeds selection.

Q2: Are cartridge seals API-682 qualified?
A: We supply standard cartridge seals and API-682 qualifying configurations on request. API-682 covers seals for shaft diameters typically from ~20 mm to 110 mm and prescribes piping plans and qualification testing. For hazardous services, request an API-682 compliant variant.

Q3: How long is lead time?
A: Standard stock sizes (25–127 mm) typically ship within 3–7 business days; engineered or exotic-material seals require a longer lead time (varies by specification). (Adjust to your actual lead times when you publish.)

Q4: Do you provide CAD and datasheet?
A: Yes — downloadable datasheet (PDF) and 2D/3D CAD packages are available per model. See download links below.

Q5: Can you supply spare parts?
A: Yes — spare seal faces, set kits, O-rings and gland kits are stocked per model.

E-E-T-A

To maximize conversions and satisfy buyer due diligence, include these E-E-T-A elements on the product page:

  1. Engineer-verified datasheet with materials, limits and a mechanical drawing (author name + date).

  2. Third-party certificates: API qualification test report (if API variant), material certificates (EN 10204 3.1), and test traces for face hardness.

  3. Case study / short project reference (1-2 lines) showing real installed service and measured MTBR improvement.

  4. Installation video & step-by-step PDF authored by your field engineer to demonstrate correct installation.

  5. Warranty & test policy (e.g., 12-month warranty, 100% factory sealing test).

Product catalog & downloads

Technical support & aftermarket

We offer pre-sales technical selection support, installation supervision, and full spare parts kits. For emergency replacements we can ship standard stock items worldwide.

Contact & purchase

Company: AoHong Group — Hengshui Aohong (Seals & Engineered Components)
Sales & Technical Inquiry:

    • Email: sales@aohongglobal.com (for datasheet requests and fast quotes)

    • Phone: +(86) 153 7318 1024 (please replace with your official number)

Provide pump tag and operating conditions when requesting a quote to speed response.

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