Product Overview
The Enardo ES-665 Spring-Loaded Thief Hatch represents the next generation of storage tank access and pressure relief technology, engineered specifically to help operators significantly reduce fugitive emissions. Designed with an advanced sealing system that delivers ultra-tight emissions performance while maintaining reliable pressure and vacuum relief, the ES-665 helps facilities improve environmental compliance, reduce valuable product loss, and support emissions reduction initiatives without sacrificing dependable operation.
Building on decades of Enardo tank protection expertise, the ES-665 combines secure manual access for gauging and sampling with automatic pressure and vacuum relief in a single, rugged assembly. Its spring-loaded design remains tightly sealed during normal operation and opens only when the tank reaches its specified pressure or vacuum setting, helping protect atmospheric storage tanks from damage while minimizing unnecessary vapor loss.
Manufactured from durable, non-sparking aluminum, the ES-665 is designed for demanding oil & gas, petrochemical, and industrial storage applications. It mounts to a standard 8-inch API bolt pattern, making it an excellent choice for both new installations and upgrades from older thief hatch designs.
Features
- Advanced low-emissions sealing technology
- Ultra-tight sealing performance to help reduce fugitive emissions
- Provides both pressure and vacuum relief in one assembly
- Spring-loaded design for reliable operation
- Allows convenient manual tank gauging and product sampling
- Positive latching cover with secure sealing
- Durable non-sparking aluminum construction
- Standard 8-inch API bolt pattern for straightforward installation
- Available in multiple factory pressure and vacuum settings
Typical Applications
- Crude oil storage tanks
- Condensate tanks
- Produced water tanks
- Chemical storage tanks
- Petroleum terminals
- Tank batteries and production facilities
- Industrial process storage vessels
Benefits
- Helps reduce fugitive emissions and VOC losses
- Supports environmental compliance initiatives
- Minimizes valuable product evaporation
- Protects storage tanks from excessive pressure and vacuum conditions
- Provides convenient access for manual gauging and sampling
- Suitable for both new installations and retrofit applications
- Designed for long service life in demanding industrial environments
Specifications
- Manufacturer: Emerson | Enardo
- Model: ES-665
- Type: Spring-Loaded Thief Hatch
- Construction: Aluminum
- Mounting Pattern: Standard 8-inch API
- Function: Manual tank access with integrated pressure and vacuum relief
- Pressure/Vacuum Settings: Available in multiple factory-configured options
- Performance: Tight to 0.10 SCFH at 90% of set pressure (68°F / 20°C)
- Available Pressure Settings: 4, 6, 8, 12, 16, 24, and 32 oz./sq. in.
Changing pressure setting requires change of spring sold separately - Vacuum Settings: 0.4, 0.9, and 3.5 oz./sq. in.
Changing vacuum setting requires change of spring sold separately - Bolt Pattern: Standard 8-inch API
- Casting Material: Aluminum
- Pressure Gasket Options: HNBR (standard), Fluorosilicone, Viton®, EPDM
- Vacuum Gasket Options: Fluorosilicone (standard), Viton®, EPDM Food Grade
- Optional Equipment Sold Separately: Base Gasket, Bolt Set, Non-Corrosive Coating, Bonding Strap, and Thrust Bearing
Manufacturer Page: Emerson / Enardo ES-665
The Emerson Enardo ES-665 delivers industry-leading emissions control while providing the dependable pressure protection and convenient tank access operators have come to expect from Enardo products. Whether installed on new storage tanks or replacing older thief hatches, the ES-665 offers an effective solution for improving sealing performance, reducing product loss, and supporting long-term environmental compliance.
If you are replacing an older Enardo 660 thief hatch or are unsure which pressure or vacuum setting is required for your application, please contact us. Our experienced staff will be happy to help identify the correct replacement model for your tank.
