Double Block and Bleed Valve

In high-risk industries such as oil, gas and chemical, the safe isolation of piping and equipment is critical to preventing leaks and protecting people and the environment. Traditional valve systems may require multiple separate components to achieve safe isolation, which not only adds complexity, but also introduces potential leak points. To address these issues, the double block and bleed valve was developed. It integrates dual block and bleed functions into one compact valve body, providing increased safety and operational efficiency.

What is a double block valve?

A double block value is a valve device that incorporates two block valves in series within a single body to provide double isolation. It is designed to provide improved media cutoff and isolation in piping systems where a high degree of safety and reliability is required.

Appliance

Oil and gas industry: For pipeline isolation, equipment maintenance, measurement and sampling and other key links.
Chemical industry: Handling toxic, harmful and corrosive media to prevent environmental pollution and safety accidents.
Power and energy: To provide safe isolation in high-pressure steam and condensate systems.
Offshore and marine: Ensure the safe operation of offshore platforms and ship piping systems.

What is a bleed valve?

A bleed value, also known as a bleed valve or relief valve, is a valve device used to discharge liquid, gas or pressure from a system or equipment. Its primary function is to relieve pressure within a system, discharge accumulated media, or provide safe operating conditions during maintenance and overhaul. By means of an automatic control device, such as a pressure sensor or float device, the valve will automatically open or close when the system reaches a set condition.

Appliance

• Oil and gas industry: Used for pipeline and equipment emptying, pressure release, to prevent accidents.
• Chemical industry: Discharge of toxic and harmful media to ensure equipment safety and environmental protection.
• Power industry: In the steam system, discharge condensate and air, improve system efficiency.
• Water treatment: Discharge air or dirt in the system to ensure water quality and system operation.

Advantages of Double Shutoff Relief Valves

1. Improved safety: By integrating two shut-off valves and a venting valve in one valve body, it provides double isolation and venting functions to maximize the prevention of media leakage and protect the safety of personnel and equipment.
2. Reduced leakage points: The integrated design combines multiple valve functions into one valve body, reducing piping connections and sealing surfaces and lowering the risk of potential leakage.
3. Saving space and weight: Compared with traditional multi-valve systems, double cut-off and bleeder valves take up less space and weigh less, which facilitates the compact design of piping systems and is particularly suitable for applications with space constraints.
4. Leak detection capability: Through the intermediate air release valve, the sealing performance of the upstream cut-off valve can be detected, and leaks can be detected and dealt with in a timely manner to ensure the reliability of the system.
5. Improve system reliability: Double isolation provides additional security, even if one valve fails, the other valve can still effectively stop the flow of media, to protect the continuous operation of the system.
6. Wide range of application: Applicable to a variety of high-risk media and harsh working conditions, such as high pressure, high temperature, corrosive media, etc., to meet the safety requirements of different industries.
7. Environmental performance: Effectively prevent media leakage, and reduce pollution of the environment, in line with environmental regulations and sustainable development requirements.

Attention When Selecting Double Shutoff Exhaust Valves

Working pressure and temperature

• Could you determine the maximum working pressure and temperature that the valve will be subjected to and select a valve that can meet these conditions
• Ensure that the pressure rating of the valve meets the system requirements to avoid safety hazards caused by overpressure.

Media characteristics

• Consider the chemical properties of the medium being handled, such as corrosivity, toxicity, viscosity and particle content.
• Select the valve body and sealing materials compatible with the medium to prevent corrosion and leakage.

Valve Type

• Select the appropriate type of valve according to the application requirements, such as ball, gate, globe or plug valves.
• Different types of valves differ in sealing performance, opening and closing speed and flow control.

Connection Method

Determine the connection method of the valve, such as flange connection, threaded connection, welded connection and so on.
Make sure the connection method meets the design requirements of the piping system and is convenient for installation and maintenance.

Valve Size

According to the size of the pipeline and flow requirements, select the appropriate valve caliber.
Too large a valve may increase the cost, and too small a valve will restrict flow and affect system performance.

Material Selection

Materials such as valve body, valve stem, seals, etc. should be selected according to the medium and working conditions.
Commonly used materials are stainless steel, carbon steel, alloy steel, copper alloy and so on.

With its excellent safety performance and efficient design, the double cut-off and bleed-off valve is an indispensable key component in the industrial sector. It not only simplifies piping systems and reduces potential leak points, but also enhances ease of operation and maintenance.

Double Block and Bleed Valve and Filter Regulator Valves

DBB valves are mainly used for safe isolation and leakage prevention to ensure that fluids are not accidentally released during maintenance or servicing, and are suitable for use where high pressure or hazardous fluids are present.
Filter regulator valves, on the other hand, are used to control fluid flow and pressure while filtering out impurities from the system to protect downstream equipment.
The two can be used in combination, with the DBB valve providing safety and security while the filter regulator valve ensures fluid quality and efficient system operation. This integration enhances the overall safety and reliability of the system.

Summary

Double Block and Bleed (DBB) valves play a critical role in isolating and protecting systems in various industries, particularly in oil and gas, chemicals, and water treatment. These valves ensure safety by providing a secure barrier, preventing leaks, and allowing for safe maintenance and inspection.

AOBL is a well known manufacturer specializing in fluid handling products, especially Air Operated Double Diaphragm Pumps. Offering a comprehensive range of pumps including electric diaphragm pumps and progressive cavity pumps for a variety of industrial applications. These pumps are manufactured using durable materials that are resistant to corrosion and abrasion, ensuring long-term use even in harsh environments. Feel free to contact us for customized pump water treatment solutions.