Self-Contained Hydraulic: Emergency Shutdown Systems & Surface Safety Valves

Self-Contained Hydraulic: Emergency Shutdown Systems & Surface Safety Valves


Stream-Flo’s Crown self-contained hydraulic valve actuation systems are used for the automatic closing of gate valves on wellheads and flow lines under emergency conditions, such as emergency shutdown systems and surface safety valves. The system consists of a hydraulic actuator, a manual hydraulic pump and control assembly, a reverse-acting gate valve, and some form of tripping control(s).

The system is self-contained and requires no flow line pressure, compressed air, gases or electricity for power. Instead, the system utilizes its own clean, contaminant-free, closed-loop hydraulics to power and control the actuation component. This makes it ideal for use in remote locations and in applications where a power source for actuation is unavailable, unreliable or too costly to produce and/or maintain.

Proven in extreme conditions around the world, Crown self-contained hydraulic valve actuation systems are API 6A certified and SIL 3 capable to provide reliable protection of personnel, facilities, resources and the environment.

No emissions icon 150 x 150As both a personnel and environmental benefit, the Stream-Flo self-contained hydraulic valve actuation system doesn't release control fluid (gases or liquids), produced or otherwise, to the atmosphere or empty it on the ground during the actuation process, either of which are characteristics of many actuation systems that use produced fluids (gases or liquids) as their power source. This feature greatly enhances operator and environmental safety.

Depending on your requirements, Crown self-contained hydraulic valve actuation systems can be triggered in a number of ways:

  • Sensor – Fire
  • Sensor – Flow
  • Sensor – Gas
  • Sensor – Level
  • Sensor – Pressure
  • Sensor – Rate-of-pressure-drop
  • Sensor – Temperature
  • Solenoids
  • Other application requirements


Crown self-contained hydraulic valve actuation systems can be applied as:

  • Emergency Shutdown Systems (ESDs)
  • High Integrity Protection Systems (HIPSs)
  • High Integrity Pressure Protection Systems (HIPPSs)
  • Shutdown Valves (SDVs)
  • Surface Safety Valves (SSVs)

In the following applications:

  • Well – Conventional
  • Well – Gas Storage
  • Well – High Pressure
  • Well – High Temperature
  • Flowlines
  • Manifolds
  • Skids
  • Water Disposal


Self-Contained Hydraulic Design Features: Actuator

The actuator hydraulically opens and closes upon release of hydraulic pressure. Modular design allows the actuator to be changed independent of the gate valve and bonnet assembly, thus providing ease of service or replacement.

Self-Contained Hydraulic Design Features: Assembly

Built-in gate stops, both upper and lower, are incorporated in the bonnet assembly. This enables the valve and bonnet to be completely assembled and stroke set independent of the actuator. A metal-to-metal stem back seat provides a means of sealing to isolate the stem-packing cavity from the flow medium in the event of a stem packing failure in addition to providing an upper travel stop for the gate.

Self-Contained Hydraulic Design Features: Pump Control Unit

The Pump Control Unit’s function is to provide a self-contained hydraulic, closed-loop power source for both the actuator and its control circuits, thus eliminating the need for an external power source. The use of the system's own clean hydraulic fluid as an operating medium ensures that the actuator and its control circuits are never in contact with the produced fluid (gases or liquids) nor a possibly contaminated external power supply. This also ensures the system is never contaminated by possible atmospheric or environmental contaminants.

This unit, designed for ease of removal and modular component replacement, consists of a manual pump, a pressure-reducing valve with a built-in accumulator, and a manual override/manual shutdown valve. The check valve in the pump provides leak-tight checking of the high-pressure hydraulic fluid back flow, ensuring reliable performance and low maintenance. The large suction filter in the pump provides high flow and extended trouble-free service life.



API 6A Sizes: 1-13/16” to 11”

API 6A Pressure Ratings to 20,000 psi

API 6A Temperature Classifications K to Y (-75°F/-60°C to +650°F/+345°C)

API 6A Material Classes AA to HH

API 6A Performance Requirements 1 & 2

API 6A Product Specification Levels 1, 2, 3, 3G & 4

SIL 3 Capable

Fire-Safe Capable


Operating media: Clean hydraulic fluid

Pump Control Unit

Component materials: Anodized aluminum and stainless steel (optional materials available upon request)

Controls & Accessories

  • Crown Access Tees
  • Crown Pilot Isolation Valves
  • Crown Pump Control Units - Electro-Hydraulic 
  • Crown Pump Control Units - Remotely Mounted
  • Custom Engineered Spool Pieces
  • Custom Packaged Actuation Systems
  • Indicator Rod Protectors
  • Limit Switches
  • Lock Open Devices
  • Lock Out of Service Devices
  • Theft Proof Enclosures
  • Other application requirements



Crown Actuated Valves & Controls Brochure

Technical Bulletins

Available upon request. Email us at


Contact Us

* = required fields