Signs You Need Seal Service
Mechanical seals should run leak-free for extended periods. These symptoms indicate seal problems:
- Visible Leaks: Product dripping or spraying from seal area. Any visible leak indicates seal failure.
- Excessive Seal Water Consumption: If seal flush water consumption suddenly increases, seal faces may be worn.
- High Seal Temperature: Seal area running hot (>180°F) indicates cooling problems or seal face damage.
- Unusual Noise: Squealing or grinding from seal area indicates dry running or contamination between faces.
- Product Contamination: Process fluid contaminated with seal flush water or vice versa.
- Bearing Failure: Often caused by product leaking past seal and entering bearing housing.
- Increased Power Consumption: Damaged seal faces create friction, increasing power draw.
- Short Seal Life: Seal lasting less than 6 months indicates underlying problems.
- Crystallization at Seal: Product crystallizing or solidifying around seal indicates temperature or flush problems.
- Vibration Increase: Seal problems can cause shaft vibration as face friction increases.
Types of Seals We Service
We work with all mechanical seal configurations from all manufacturers:
Component Seals
Description: Individual parts assembled on pump shaft during installation.
Advantages: Most economical option, repairable in some cases, widely available.
Disadvantages: Requires precise assembly, setting dimensions critical, more labor to install.
Typical Applications: Water service, light hydrocarbons, general purpose pumps.
Installation Time: 2-4 hours
Cartridge Seals
Description: Pre-assembled, pre-set seal that slides onto shaft as complete unit.
Advantages: Easy installation, no setting required, less installation errors, cleaner installation.
Disadvantages: Higher initial cost, not repairable (replace entire cartridge).
Typical Applications: All applications, especially where installation errors are common.
Installation Time: 1-2 hours
Split Seals
Description: Seal that splits in half for installation without removing coupling.
Advantages: No coupling removal needed, ideal for large pumps, reduces downtime.
Disadvantages: Most expensive, split joint is potential leak path, requires careful alignment.
Typical Applications: Large pumps, difficult access situations, spacer-less designs.
Installation Time: 2-3 hours
Specialty Seals
Types We Handle:
- Metal Bellows Seals (no dynamic O-rings)
- Gas Seals (dry running, non-contacting)
- Mixer/Agitator Seals (large shaft, high vibration)
- Slurry Seals (abrasive service, hard faces)
- High Pressure Seals (>300 PSI)
- High Temperature Seals (>400°F)
- API 682 Compliant Seals (refinery standard)
Seal Arrangements We Handle
We install and service all standard seal arrangements per API 682 and manufacturer specifications:
Single Seals
Arrangement 1 (Balanced)
Configuration: Seal faces on atmospheric side of impeller.
Advantages: Lower face loading, longer life, suitable for high pressures.
Applications: High pressure, high temperature, most common arrangement.
Arrangement 2 (Unbalanced)
Configuration: Seal faces on process side of impeller.
Advantages: Lower cost, simpler design, compact.
Applications: Low pressure (<150 PSI), clean fluids, water service.
Dual Seals
Back-to-Back (Arrangement 2 Dual)
Configuration: Two seals with barrier fluid between at higher pressure than process.
Advantages: Zero emissions, seals pressurized inward.
Applications: Toxic, flammable, or expensive fluids. Most common dual seal.
Face-to-Face (Arrangement 3 Dual)
Configuration: Two seals with buffer fluid between at lower pressure than process.
Advantages: No pressure vessel for barrier fluid needed.
Applications: When atmospheric buffer acceptable, less critical services.
Tandem Seals (Arrangement 4)
Two seals in series with buffer fluid at atmospheric pressure. Primary seal contains process, secondary seal is backup. Used when zero emissions critical but pressurized system not desired.
Seal Support Systems (API Plans)
Proper seal support systems are critical for seal life. We install and maintain all API Plan configurations:
| API Plan | Description | When Used |
|---|---|---|
| Plan 11 | Flush from pump discharge | Clean fluids, low temperature, simple systems |
| Plan 13 | Flush from external source | When discharge fluid unsuitable (hot, dirty, viscous) |
| Plan 23 | Flush from discharge through heat exchanger | High temperature fluids needing cooling |
| Plan 31 | Flush with cyclone separator | Fluids with solids that must be removed before seal |
| Plan 32 | Flush from external source through heat exchanger | Very hot or dirty fluids |
| Plan 52 | Unpressurized barrier fluid reservoir (dual seals) | Dual seal with buffer fluid |
| Plan 53 | Pressurized barrier fluid with bladder accumulator | Dual seal, most common for zero emissions |
| Plan 54 | External pressurized barrier fluid system | Multiple pumps sharing barrier system, critical applications |
Our Seal Service Process
Failed Seal Analysis
We examine the failed seal to determine root cause, not just symptoms.
- Photograph failed seal components
- Inspect seal faces for wear patterns, heat damage, chipping
- Check elastomers for chemical attack, heat damage, extrusion
- Examine springs for corrosion, cocking, or breakage
- Identify failure mode: dry running, abrasion, chemical attack, heat, installation error
- Determine root cause to prevent repeat failure
Shaft & Housing Inspection
Seal components must mate with shaft and housing. We verify conditions are acceptable.
- Shaft Surface Finish: Must be 32 RMS or better. Machine if rough or scored.
- Shaft Runout: Check TIR, must be <0.002". Straighten or replace shaft if excessive.
- Seal Chamber Face: Must be perpendicular to shaft within 0.002". Machine if needed.
- Chamber Concentricity: Seal chamber must be concentric with shaft.
- Corrosion Check: Look for corrosion damage that could affect seal performance.
- Sleeve Condition: If shaft sleeve present, check for wear, damage, looseness.
Seal Selection & Sourcing
Select proper seal for application and source quickly.
- Exact OEM replacement when possible (best fit and performance)
- Equivalent aftermarket if OEM unavailable or cost prohibitive
- Upgrade opportunities: component to cartridge, single to dual
- Material selection for application (faces, elastomers, metal components)
- API 682 compliance when required
- Emergency cross-reference if unusual seal needed fast
- Rush delivery available (same-day or next-day for common seals)
Professional Installation
Proper installation is critical. Most seal failures are installation-related.
- Clean all surfaces thoroughly (no dirt, debris, old gasket material)
- Inspect for damage or burrs that could damage new seal
- Lubricate seal with compatible fluid (not petroleum jelly unless specified)
- Install carefully to avoid damage to faces or O-rings
- Set proper seal face gap or compression per manufacturer specs
- Torque all bolts to specification (prevent gasket leaks)
- Connect flush/barrier system properly with correct flow direction
- Verify no debris trapped between faces
System Verification & Testing
Test before returning to service. Catch problems before they become failures.
- Verify flush system flow (must have flow before starting pump)
- Check barrier fluid level and pressure (dual seals)
- Perform leak test if possible before startup
- Start pump and verify no leaks immediately
- Monitor seal temperature during initial run (should stabilize <180°F)
- Listen for unusual noises (squealing indicates problems)
- Verify proper flush flow continues during operation
- Provide run-in period recommendations
Documentation & Follow-Up
Document work performed and schedule follow-up to ensure success.
- Record seal manufacturer, model, materials
- Document API Plan and flush system configuration
- Provide installation date for maintenance tracking
- Note any abnormalities or concerns
- Provide operating recommendations
- Schedule 30-day follow-up inspection
- Warranty documentation
Common Seal Failure Causes
Understanding failure causes helps prevent repeat failures:
Dry Running
Cause: Pump ran dry, insufficient flush, vapor lock in seal chamber.
Prevention: Flow switches, level controls, proper API Plan, adequate NPSH.
Abrasive Solids
Cause: Solids getting between seal faces causing rapid wear.
Prevention: Plan 31 (cyclone separator), hard seal faces (SiC), proper filtration.
Chemical Attack
Cause: Incompatible seal materials for fluid being pumped.
Prevention: Proper material selection, chemical compatibility review.
Heat Damage
Cause: Excessive heat generation, inadequate cooling.
Prevention: Proper flush system (Plan 23), face material selection, adequate flow.
Installation Error
Cause: Wrong setting dimension, contamination during install, damaged during assembly.
Prevention: Follow OEM procedures, use proper install tools, professional installation.
Misalignment
Cause: Pump/motor misalignment causing excessive shaft runout at seal.
Prevention: Laser alignment to ±0.002", check shaft runout, verify soft foot eliminated.
Other Causes
Shaft deflection, excessive vibration, corrosion, wrong seal for application, poor flush system design.
Seal Material Selection Guide
Proper material selection is critical for seal performance and life:
Seal Face Materials
Carbon vs Ceramic
Applications: Water, light chemicals, general purpose
Temperature: Up to 400°F
Pressure: Up to 300 PSI
Cost: $$ (economical)
Notes: Most common combination. Carbon is sacrificial material, ceramic is hard face.
Silicon Carbide vs Silicon Carbide
Applications: Abrasive slurries, chemicals, high pressure
Temperature: Up to 800°F
Pressure: Up to 600 PSI
Cost: $$$$ (expensive)
Notes: Extremely hard, abrasion resistant, chemical resistant. Required for harsh services.
Tungsten Carbide
Applications: Extreme abrasion, slurries, severe erosion
Temperature: Up to 500°F
Pressure: Up to 500 PSI
Cost: $$$$$ (most expensive)
Notes: Hardest commonly available face material. For worst abrasive conditions.
Elastomer (O-Ring) Materials
| Material | Temperature Range | Chemical Compatibility | Common Applications |
|---|---|---|---|
| Buna-N (Nitrile) | -40°F to 225°F | Hydrocarbons, water, oils | Most common, general purpose |
| EPDM | -65°F to 300°F | Water, steam, caustic, acids | Water systems, steam, chemicals |
| Viton (FKM) | -20°F to 400°F | Acids, solvents, high temp | Chemical service, high temp |
| Kalrez/FFKM | -15°F to 600°F | Universal chemical resistance | Severe chemical service |
| PTFE (Teflon) | -100°F to 500°F | Excellent chemical resistance | Sanitary, chemical, high temp |
Metal Component Materials
- 316 Stainless Steel: Standard for most applications. Good corrosion resistance, reasonable cost.
- Alloy 20: Sulfuric acid service. Better corrosion resistance than 316 SS for specific chemicals.
- Hastelloy C: Severe corrosion environments. Hydrochloric acid, chlorine, wet chlorine gas.
- Alloy 400 (Monel): Hydrofluoric acid service. Excellent resistance to HF and alkalies.
- Duplex Stainless: High strength with good corrosion resistance. Offshore, chloride environments.
Seal Life Expectancy
Properly selected and installed seals should provide years of service:
| Service Conditions | Expected Seal Life | Factors |
|---|---|---|
| Clean water, ideal conditions | 3-5 years | Proper materials, good alignment, adequate flush |
| Light chemicals, good maintenance | 2-3 years | Compatible materials, proper API Plan |
| Abrasive service (slurries) | 1-2 years | Hard seal faces (SiC), proper flush system |
| Severe conditions (high temp/pressure) | 6-18 months | Specialty materials, excellent maintenance |
Factors Affecting Seal Life:
Positive Factors:
- Proper material selection
- Correct installation
- Adequate cooling/flushing
- Good pump alignment
- Clean operating environment
- Preventive maintenance
Negative Factors:
- Dry running incidents
- Contaminated flush water
- Poor alignment/high vibration
- Inadequate cooling
- Abrasive or corrosive fluids
- Frequent starts/stops
Seal Replacement Pricing
Labor Costs (Installation):
| Pump Size | Component Seal | Cartridge Seal | Split Seal |
|---|---|---|---|
| Small (<10 HP) | $300-600 | $200-400 | $400-700 |
| Medium (10-100 HP) | $600-1,500 | $400-1,000 | $800-1,800 |
| Large (>100 HP) | $1,500-5,000 | $1,000-3,500 | $2,000-6,000 |
Seal Costs (Parts - Varies Widely):
| Seal Type | Small Pump | Medium Pump | Large Pump |
|---|---|---|---|
| Component Seal (standard materials) | $100-500 | $300-1,500 | $1,000-5,000 |
| Cartridge Seal (standard materials) | $300-1,200 | $800-3,000 | $2,000-10,000 |
| Dual Seal (back-to-back) | $600-2,500 | $1,500-6,000 | $4,000-20,000 |
| Specialty Seals (API 682, exotic materials) | $500-3,000 | $2,000-10,000 | $5,000-30,000+ |
Note: Seal prices vary dramatically based on size, materials, and manufacturer. Specialty seals with Hastelloy components and SiC faces cost significantly more than standard 316SS/Carbon-Ceramic seals.
Critical Seal Inventory Program
For critical pumps that can't afford downtime, we offer seal inventory programs:
How It Works
- We identify your critical pumps
- Stock proper seals for each
- Store in our climate-controlled facility
- Guaranteed 4-hour installation response
- Annual inventory management fee
- Seal invoiced when used
Benefits
- Eliminate lead time wait
- Guaranteed parts availability
- Reduce emergency downtime
- Priority service response
- Budget planning easier
- We manage inventory for you
Annual Fee: $500-2,000 per pump depending on seal cost and quantity. Typically pays for itself with first emergency avoided.
Seal Service Warranty
90-Day Labor Warranty
Covers:
- Installation workmanship
- Proper procedures followed
- Correct setting/compression
- Leak-free operation
If seal leaks due to installation error, we return and correct at no charge.
Seal Manufacturer Warranty
Coverage:
- Manufacturer defects in materials
- Manufacturing defects
- Typically 1 year from installation
- We coordinate warranty claims
Manufacturer warranty void if installation improper or operating conditions outside seal design.