Mechanical Seal Style CPH
Dry-Running, Non-Contacting Containment Gas Seals
For secondary containment, minimizing process emissions and simplifying external support systems
Flexaseal Style CPH seals are non-contacting dry gas seals designed to provide secondary vapor containment and full pressure wet backup seals in high-duty applications like light hydrocarbons, crude oil, and other hazardous services.
- Optimized bi-directional laser-etched liftoff patterns maintain the non-contacting gas seal, reducing wear and power consumption.
- Designed to meet stringent emissions standards for light hydrocarbons and other hazardous products when supported with Plan 72/76 vapor containment systems, directing leakage to flare.
- Functions as a backup wet seal when primary containment fails, ensuring operational safety, even under high pressure leakage.
- Can operate effectively as a single seal for blowers, turbines, and vertical sump pumps, where dry-running and low emissions are required.

Mechanical Seal Style CPH
Design Features & Benefits
Common Applications
- Crude oil
- Bitumen
- Produced water
- Boiler feed water
- Amine
- Ammonia
- Seawater
- Light hydrocarbons
Specifications
Materials of Construction
Rotary Faces: | Silicon carbide |
Stationary Faces: | Antimony impregnated carbon/graphite |
Springs: | Hastelloy C-276 |
Metal Parts: | 316 stainless steel, Alloy 255, Hastelloy C-276 |
O. Rings: | Fluoroelastomers, EPDM, TFEP, Perfluoroelastomers |
Operating Parameters
Max Temp: | 250°F (121°C) |
Typ. Operating Pressure: | 0 – 15 psi (0 – 1 bar) |
Max Containment Pressure: | 1,500 psi (103 bar) |
Max Speed: | 6,000 FPM (30.5 m/s) |
Note: Max Temperature / pressure / speed indicate operating extremes independently and do not imply the seal will function at these extremes at the same time. Contact Flexaseal if in doubt.
Downloads
For more information on the CPH
Quote Request
Depending on your specific needs and application, Flexaseal can help you identify the ideal products. Contact us to tell us about your needs and request a quote.
Type A | Category 2/3 Non-Contacting Dry Seals – Arrangement 2
The Flexaseal Style CPH addresses the challenges of sealing high pressure process fluids with low specific gravities by provide a safe and effective secondary non-contacting gas seal. The seal design is highly adaptable to meet specific application needs and comes standard with:
- High duty seal face materials.
- Antimony impregnated carbon/graphite primary rings are robustly designed to contain highpressure leakage in the event of inboard seal failure.
- Sintered silicon carbide mating rings.
- Precision laser-etched face topography separates the seal faces ensuring non-contacting operation as a secondary seal.
- Canted coil springs center sensitive components for smooth operation.
- Two-piece sleeve design withstands extreme thrust loads for reliability under strain.
- Ultra-polished dynamic O-ring surfaces and backup ring design minimize drag for fast responses to changing conditions.
- Stationary design allows for high-peripheral speeds
Style CPH seals can be configured with optional support features to meet application specific requirements, including:
- Plan 72 – buffer gas sweep of inner seal leakage dilutes emissions to atmosphere
- Plan 75 – condensing leakage collection system redirects inner seal leakage away from the containment seal
- Plan 76 – non-condensing leakage vapor collection system (e.g. vent to flare) redirects inner seal leakage away from the containment seal
The Style CPH leakage containment solution can be incorporated to the following seal styles:
- Style HPPS
- Style 58A
- Others, as developed