ESD Valve System

ZE-ESD Module

Zero-Emission Emergency Shut-off (ESD) for valves that require an automatic fail-safe position in locations where power is not available and fugitive emissions not permitted.

Cowan’s ZE-ESD Module is a self-contained Hydraulic Emergency Shutdown System (ESD) to automate valves that require a fail-safe position in locations where power
is not available.


This self-contained Emergency Shutdown (ESD) module can be used with rotary or linear valves and consists of a hydraulic manifold block, a leakage compensating accumulator, an oil reservoir, and hydraulic control components.

In normal operation the system holds the valve in its “normal” or “operational” position locked in place.

These systems are engineered by Cowan to be retrofitted onto existing pipelines without taking the valve out of service.

ESD Valve Safety

In the event of a failure, triggered by an ESD signal, the system will use stored hydraulic pressure or a pre-compressed spring  to move the valve actuator to the desired fail-safe position (open or close) ensuring an automatic fail-safe system without the need for external power.

This system is designed to minimize maintenance and is engineered for tough heavy-duty industrial applications to operate valves with high thrusts and torques.


Interactive Icons

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rotary esd valve system

Hydraulic Bladder Accumulator

To compensate for leakage in the hydraulic system


Manual Hand Pump

To manually return the valve to its “operational” position and re-arm back the system


Hydraulic Control Manifold

Operational of manual and/or solenoid operated directional valves, flow controls and pressure gauges.


Hydraulic Oil Reservoir

Designed to contain the amount of hydraulic fluid required by the system.



Built-in Rotary Beacon or LVDT for position feedback


Zero Emissions, Zero Energy required

Maximum working pressure 1500 PSI-g

Engineered for heavy-duty applications, high thrust, high torque requirements


Electrical or hydraulic ESD signal


Mechanical fail with pre-compressed spring or hydraulic accumulator


Self-contained design, can be used for linear or rotary valve actuators


For fail-safe systems (ESD & PSD), when power is not available


Secondary accumulator for leakage compensation ensures drift-free performance for weeks at a time.

The ZE-ESD Module is part of an integrated solution providing an automatic ESD system to emergency shutoff valves in locations where power is not available.

Integration Examples

ESD Valve System Specifications


Automatic Emergency Shutdown Valve System

Ambient Temperature rating

-50° to + 40° C

Pump working pressure

1,500 PSI-g

Max Available thrust

See below thrust chart. Higher values available upon request
* Consult Factory

Max available torque

See below torque chart. Higher values available upon request
* Consult Factory


Province CRN as applicable

Linear Valve Types

Knife Gate Valve, Gate Valve, Globe Valve, Pinch Valve, etc.

Rotary Valve Types

Ball Valve, Butterfly Valve, Plug Valve, etc.

Common Applications

Conventional, gas storage, HP/HT Wells. Pipelines, tank farms and others

Common Terms

Surface safety valve, safety shutoff valve, emergency shutdown valve (ESDV), hydraulic shutdown valve, shutdown valve (SDV)

Learning Center for Automatic ESD Valve System

What is an ESD Valve?

Emergency shutoff valves (ESD valves) are specifically designed to shut the process, often carrying hazardous media, in the case of an undesirable event. For this reason, they must be actuated to automatically respond to a signal triggered by such an event. They are key components in a safety instrument system providing protection to operators and the environment.

Where are ESD valves most used?  

These valves can be found mostly in the oil and gas industry, installed in pipelines, production wellheads or tank farms. Typically, they are in very remote locations where sources of energy are limited or not available. These valves are critical to process safety and need a reliable self-powered automatic shutdown system.

emergency shutdown valve custody transfer point

Typical remote pipeline application 

ESD Valve Systems Applications

Cowan Dynamics has engineered the ZE-ESD, zero emission self-contained Hydraulic Emergency Shutdown (ESD) system.

This system is ideal for valves in remote locations that require a self-powered automatic failure position. This system utilizes hydraulic pressure to actuate the valve to the desired failure position in the event of an ESD signal loss which can be from pressure pilots, solenoid valves, switches, transducers, or others depending on the application. The ZE-ESD is compatible with emergency shutoff linear and rotary valve actuators such as gate valves, ball valves, butterfly valves, etc.


Download a case study below to learn more about how Cowan’s ZE-ESD can improve the reliability of your API emergency shutdown valves in your midstream pipeline distribution network.

About the ZE-ESD Module  

The ZE-ESD Module integrated to an appropriate valve actuator is capable of achieving up to 118,000 Lbf or 131,000 in-lbs depending on the type of valve being actuated and subject to their size. Exposure to harsh conditions is another challenge that ESD valve actuators must withstand. Note, the ZE-ESD Module is only a hydraulic source and needs an actuator to produce thrust/torque.


For this reason, the ZE-ESD system has been engineered to operate in ambient temperatures as low as -50C and as high as +40C, with an environmental protection to IP66 and and certified for use in hazardous areas.

How The ZE-ESD Valve System Works? 

This self-contained ZE-ESD system can be used in conjunction with linear or rotary valve actuators and consists of a hydraulic manifold block, a leak-compensating accumulator, a small reservoir, and a hydraulic hand pump.  

Linear Integration Example

emergency shutdown valve system

In normal operation, the system holds the valve in its “normal” or “operational” position, locked in place as it is connected to a doubleacting actuator. No additional pressure or energy is needed to compress a spring. This design helps to reduce pressure losses, inspections, and costs.   

In the event of a failure triggered by the ESD signal, the system will use the stored hydraulic pressure in the accumulator to move the valve to the desired failure position, ensuring a safe automatic system without the need for external power. This system is designed to minimize maintenance and is built for heavyduty industrial applications to actuate valves with high thrusts and torques.