Product Introduction 

  In the production of gas wells, when occurrences of surface pipeline obstructions can arise, or failures of the choke may occur, the pipeline pressure will rise to lead to overpressure of the surface pipeline, which will be a major security risk. When the pipeline is corroded or accidentally damaged to leak, it will cause the wellhead pressure to drop. Installing an emergency cut-off device at the wellhead can effectively avoid the damage of downstream pipelines caused by wellhead overpressure and the safety accidents caused by pipeline leakage.

  At present, the product has become the standard configuration of gas field production, and has been widely used, with tens of thousands of gas wells installed in the past 20 years.

 

 

 

 Applicable Range 

   Emergency cut-off devices are widely used in petroleum and natural gas, chemical industry, metallurgy, electric power and other fields. Its main function is to cut off the pipeline fluid in case of emergency and ensure the safe operation of the pipeline.

 

 

 Function and Features 

1）Design of multiple production modes

There are four production modes: manual mode, automatic mode, time intermittent mode and pressure intermittent mode, which can realize low-pressure intermittent production in the later stage of production.

2） Design of emergency cut-off function

When the valve is opened, the locking mechanism enables the valve to be in an open state, and when the external pipeline pressure is abnormal, the locking mechanism can be automatically unlocked to realize the emergency cut-off function of the valve.

3）Design of remote starting and closing function

The remote control platform can realize the intelligent "automation"of the remote opening and closing of valves.

4）Double insurance to ensure emergency cut-off under special conditions

Under normal conditions, emergency cut-off function can be realized for both mechanical over-undervoltage and remote over-undervoltage, with an accuracy of ± 0.1MPa. In the case of power failure, the mechanical over-under-voltage realizes the valve closing function. The two control units are mutually independent and do not interfere with each other.

①Mechanical over-under-voltage cut-off design

The pipeline natural gas is used as the power to realize the emergency overpressure and underpressure cut-off, and the closing time is less than 3s. The emergency cut-off function is more stable and reliable compared with the electric control mechanical emergency cut-off function.

②Over-undervoltage cut-off design of electric control

When the pipeline pressure is abnormal, the electric control over-voltage and under-voltage realize the emergency cut-off function. The accuracy is more sensitive, with the closing time less than 3 seconds.

5） Anti-freezing blocking structure design

The valve opening structure adopts a labor-saving lever to realize the opening of high pressure and low torque, which can realize the normal opening of the valve under the condition that the valve is frozen, and thereby it can effectively prevent the freezing and blocking problem;

6）Humanized manual valve closing function

And when that valve is in an open state, it is closed in real time to enhance the  reliability of the valve closure.

7）On-site valve position status display

The real on-off state of the stop valve can be visually observed on site through the indicator rod;

             

 Technical Parameters 

1) Nominal pressure: 16 Mpa, 25 MPa, 42MPa

2) Nominal diameter: DN50, DN65, DN80, DN100, DN125, DN150

3) Working temperature: -40 ℃ ~ 80 ℃

4) Working voltage: DC12/24V

5) Explosion-proof/protection grade: ExdmbⅡb T4Gb/IP65

6) Cutoff working pressure: ≤ 16 Mpa, 25 MPa, 42 MPa

7) Remote and local emergency cut-off time: ≤ 1.5s; Valve opening time: 15s

8) Overpressure cut-off pressure: 3.0 ~ 12.0 MPa, which can be set automatically

9) Under-pressure cut-off pressure: 0.1 ~ 3.0MPa, which can be set automatically

10) Product power: 45W/standby power: 1W

11) Communication mode: MODBUS485, dry contact

 

 Execution Standards 

GB/T 12220 Industrial Valve Marking

GB/T 12221 Metal Valve Structural Lengths

GB/T 20173 Petroleum and Natural Gas Industries—Pipeline Transportation Systems—Pipeline Valves

NB/T 47008 Carbon Steel and Alloy Steel Forgings for Pressure Equipment

NB/T 47013.2 Non-destructive Testing of Pressure Equipment Part 2: Radiographic Testing

GB/T 13927 Industrial Valves—Pressure Test

JB/T 6899 Fire Test for Valves

GB/T 3836.1 Explosive Atmospheres—Part 1: Devices—General Requirements

GB/T 3836.2 Explosive Atmospheres—Part 2: Equipment Protection by Flameproof Enclosures "d"

 

 Application Cases 

At present, the emergency cutoff device of our company has been used in many gas fields, especially in the harsh environment in the north, where the temperature is below -30 ℃ in winter, but the emergency cutoff device flexible in opening and closing can still operate normally, which  solves effectively the problem of freezing and blocking of valves in low temperature environment. It has been well received by users. At present, the patented product has been widely used in onshore gas fields such as PetroChina, Sinopec and CNOOC, and has become the standard configuration for the development of tight gas fields.

 

CNOOC China United Coalbed Methane Well Site

 

A well site in Changqing Oilfield

 

A well site in Yanchang Oilfield

 

A CBM well site in China and Australia