ESD Valve System
ZE-ESD Module
Zero-Emission Emergency Shut-off (ESD) for valves that require an automatic fail-safe position where power is not available and/or the user must eliminate fugitive emissions from the actuator.

Cowan’s ZE-ESD Module is a self-contained Hydraulic Emergency Shutdown System (ESD) to automate valves that require a fail-safe position where no power source is available.
Overview
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, a small reservoir, and a hydraulic hand pump.
In normal operation the system keeps 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 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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Hydraulic Bladder Accumulator
To compensate for leakage in the hydraulic system
Manual Hand Pump
To manually return the valve to its “operational” position and arm back the system
Hydraulic Manifold
Operational manual Valves, pressure reducing valves, check valves, flow controls and pressure gauges
Hydraulic Oil Reservoir
Designed to contain the complete volume of the system
Features At a Glance
For fail-safe systems (ESD & PSD), when power is not available
Hydraulic fail-safe system with accumulator
Secondary accumulator for leakage compensation ensures drift-free performance for weeks at a time.
Engineered for heavy-duty applications, high thrust, high torques requirements
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.
The Cowan ZE-ESD Module is part of an integrated solution to provide an automatic ESD system to emergency shutoff valves where no external power source is available.

ESD Valve System Specifications
Service | 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 |
Max available torque | See below torque chart. Higher values available upon request |
Certifications | 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) |
Valve effective max stroke (In) | Max ETC (Fail close) Lbf | Max BTO (Fail close) Lbf |
28.00 | 6,710 | 8,531 |
18.00 | 10,485 | 14,255 |
12.00 | 15,098 | 19,950 |
7.00 | 26,842 | 41,193 |
4.40 | 41,940 | 52,013 |
3.00 | 60,394 | 85,396 |
2.25 | 82,203 | 124,848 |
1.70 | 107,367 | 118,828 |
*Based on the used of the module in combination with our Cowan Dynamics Hydraulic 3000 psi rated actuators (Series ML) |
Max ETC (Fail close) lb-in | Max BTO (Fail close) lb-in |
99,200.00 | 131,000.00 |
*Based on the used of the module in combination with our Cowan Dynamics Hydraulic 3000 psi rated actuators (Series CSY-H) Thrust and torque calculations done at +40C ambient temperature |
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.
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 lost 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 valves 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 system is self-contained and 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.
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 certified for hazardous area classification.
How The ZE-ESD Valve System Works?
This self-contained ZE-ESD system can be used in rotary or linear valves and consists of a hydraulic manifold block, a leak compensating accumulator, a small reservoir, and a hydraulic hand pump.
In normal operation the system keeps the valve in its “normal” or “operational” position, locked in place as it is connected to a double–acting actuator. No additional pressure or energy is needed to compress a spring. This design helps to reduce pressure losses, inspections, and cost.
In the event of a failure triggered by the ESD signal, the system will use the stored hydraulic pressure in an accumulator to move the valve to the desire failure position ensuring a safe automatic system without the need of external power. This system is designed to minimize maintenance and built for heavy–duty industrial applications to actuate valves with high thrusts and torque.