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Double Block and Bleed valve

Double Block and Bleed valve


  • Sizes: 2″-24″, ANSI and API 6A

  • Ratings: ANSI 150-2500 lbs, API 10,000-20,000 PSI

  • Materials: wide selection of materials for both body and internals: carbon steel, low alloy steels, stainless steels, Duplex, Nialloys and titanium

  • Including NACE MR-01-75 (latest revision)

Introduction to Double Block and Bleed Valve System

The Double Block and Bleed Valve is a safety control valve designed for high-pressure natural gas lines. It is a common valve that is used to reduce the risk of hazardous gas leaks from pipelines.

The Double Block and Bleed Valve has an outer shell that separates the two fittings and contains a pressure release, which releases excess pressure after it shuts off the flow in the pipe. This allows for gradual depressurization of the pipeline, preventing excessive pressure surges and potential explosions.

double block and bleed valve for your application
Double Block and Bleed Valve for Industrial Applications

The design makes it very difficult to remove without breaking it in half, so it is typically installed permanently on pipelines, although this can vary by industry standards.

A major difference between the Double Block and Bleed Valve and other types of valves is that there are no ports or openings inside of them for natural gas

Double Block and Bleed Valve are two types of valves that are used in the Industrial MRO industry, which is the manufacturing of industrial equipment.

Double Block and Bleed Valves work on a principle where the fluid pressure from one source meets pressure from another source at an orifice or gate. In other words, it forms a seal that blocks the flow of fluid to prevent over-pressurization or leaks and allows for fluid flow when it needs to happen.

A Double Block and Bleed Valve is a device that regulates the flow of air from the air compressor or blower into the brake system. It can be used to help prevent a lack of pressure.

A Double Block and Bleed Valve eliminates the need for pumping. This means that your work may be less strenuous as you will not have to pump as much. It also means that you will not have to worry about damaging a braking system if you forget to turn off your pump when finished working in an area where there is no pressure coming from an air compressor or blower.

Double block and Bleed Systems

Double block and Bleed Systems are the practice of shutting off the flow from only a single side of a valve. The disadvantages are that it takes significantly more time to shut off and open up pipe rather than DBB.

integral double block and bleed valve
integral double block and bleed valve drawings

Closing the ball valves to your working area ensures that pressure is properly blocked. The next step is to bleed any remaining pressure in the valve and piping- this will ensure that air isn’t leaking anywhere.When working with gas, make sure you close the ball valves and bleed any remaining pressure. This will ensure that all gas is removed from the piping before work begins.

Double block & bleed is used during oil, gas, or other related industries to reduce the risk of harm. Companies typically mandate this practice during any equipment work on the fields, and it has led to safer processes overall.

The Double Block& Bleed valve is a unique configuration that provides true double positive isolation. That means the valves provide pressure on both sides of the valve and have no back-flow. The configuration ensures that there is no chance for contamination or cross-contamination from one side to the other. This configuration is best suited for severe isolation services such as sewage, water,oil and gas.

Double positive isolation is a single-operating valve that has two seats. When it’s closed, these bring up the sealing against a single pressure source. This configuration allows this device to function independently from each other when needed.

The double block and bleed valve is a water-operated pump that is used to maintain pressure in a boiler. It consists of two parts: the lower double block, which includes the inlet pipe, and the upper single block, which includes the outlet pipe. The purpose of this equipment is to isolate one portion for replacement or repair while still maintaining pressure.

DBB valve’s seating will both seal high pressure and low pressure upstream and downstream.

Double Block & Bleed Valves are a type of valve designed and used to allow for isolation from both the upstream and downstream fluid flow/pressures.

Types of Double Block And Bleed Valves

To safely close your pipeline, first open the ball valves to block both the upstream and downstream sides. Close them while leaving any pressure inside overnight.DBB valves are used to control the flow of a fluid. There are many types that are available in our product range.

Integral DBB valve

Integral DBB valve is always small size, reduced port, and floating ball valve type. According to its name, it has an integrated floating ball operated by a stem with level. This floating type ball valve rotates 90 degrees freely in either direction. There are two different seat seals design available for double block and bleed – a metal seat seal or a soft seat seal.

Single Block and Bleed valve

The Single Block and Bleed Valve is used on a boiler. It is a safety valve that prevents rapid pressure build up in the steam line.

The single block and bleed valve is a safety valve on the steam line of boilers that prevents rapid pressure build-up. The single block and bleed valve consists of two separate valves that are linked to one another, and are referred to as the “Single Block” or “Bleed Valve”. The Single Block separates high-pressure water vapor from low-pressure steam, while the Bleed Valve removes excess water vapor from the system before it reaches high pressure.

The Single Valve is used in conjunction with other safety valves in order to prevent rapid pressure build up – which can lead to dangerous situations if left unchecked.

Modular DBB valve

Modular DBB valve are available in a variety of designs that are designed in accordance with ASME B16.34 & API 6D, as well as the standards that pertain to them. They’re also used in a variety of places such as waterworks applications.

Trunnion Mounted Ball or Floating Ball

The double block and bleed valve are classified into two categories, floating dbb valve and trunnion mounted Ball DBB Valve.

Trunnion monuted DBB valve is a type of API 6d trunnion mounted ball valve used in industrial applications and gas industry ,Trunnion monuted DBB valve is designed for valve operation with a single handle. It has a few benefits over the other type of trunnion mounted ball valve that are used in the market.

Floating double block and bleed valve is a valve which is designed to help reduce the pressure loss of pipelines and can relieve the fluid in case of leakage.

How are double block and bleed valves constructed?

The valve design is to provide a double block and bleed valve with two seating, body,two balls,stem,& trim. The double block and bleed valve is to provide a double checking of the upstream and downstream valves. The upstream valves are to open and close with pressure only when the downstream valves are closed.


The Double Block and Bleed Valve is the best valve for almost any application. Double block and bleed valve in closing position provides a seal when sealed closed and a seal when open to allow pressure to release.The dbb valve body material is made of durable and exceptionally corrosion resistant A182 F316 stainless steel or forged steel A105 which can be produced to meet the most demanding customer specifications.


Our double block and bleed valve, a ball valve with self-relieving seals and a bleed valve to vent the cavity, is designed for Industrial applications where corrosion is a concern. API 6D ball valve is a type of shut off valve that has a hollow sphere or ball, which is positioned in the center of the valve and turns so that material will pass through it.

Type of seats

Double block and bleed valve has a metal or a soft seat. They both have the same working principle, to exchange air between two sets of two different types of fluid. Metal type seats will work at high temperature.


Class 150 to Class 2500

Type Of Bore

Full Bore

Full bore which means the valve diameter is the same as a pipeline diameter. This type of valve is best for a pipeline.

Reduced bore

The reduced bore double block and bleed valve is a device that has an inlet, outlet, and a vent. It is used to reduce the size of the maximum pressure in a system.

End Connection

Flange end ASMEB16.5/ Treaded Screwed NPT ASME B1 .1/ Soket welded ASME B16.11

Other features Of Double Block And Bleed Valve

1.Fire Safe design


3.locking device

4.blowout resistance of stem

5.Reliable Seat Sealing

6.Top flange for actuator

7.Full port or reduced port

8.extended stem for undergroud

9.extended stem for low temperature

Double Block And Bleed Valve advantages

double block and bleed double block and bleed double

How It Works: Double Block-and-Bleed and Double Isolation-and-Bleed

DIB definition

A double isolation and bleed (DIB) valve is a type of valve that is used to vent or bleed air in and out of a cavity, which can be used to isolate piping.API defines DIB as “single valve with two seating in closed position provides a seal tightly while also allowing for pressure to escape”. DIB valves are also referred to as being configured with a double isolation and bleed (DIB) arrangement.

An API 6D double isolation and bleed valve has two seating surfaces, but one of them is closed. The closed seat provides a seal against pressure coming from a single source and the other allows for bleeding/venting between them.

Double isolation and bleed refers to the use of two separate devices that are sealed together in order to create a safe and reliable system. A bleed valve is used to release excess pressure or air built up in the system, and these valves can be found on both sides of a double isolation device.

Differences of DIB and DBB

Double isolation and bleed valves are used in manufacturing facilities to protect the process from contamination. The isolation valves isolate the process and prevent contaminants from entering the system while the bleed valves release excess pressure.

A double block and bleed (DBB) valve has two seats which are used for providing a seal against pressure coming from both ends of the valve. It also provides a means for air or fluid to be vented, bleed, or wiped off.cavity between the seating surfaces

Application, media and environmental challenges affecting valve selection

DBB valves are typically used in high-pressure applications where they are subjected to thermal expansion and contraction.

DBB valves have been around for a long time and have evolved as technology has advanced. DBB valves were originally used in the automotive industry to provide pressure relief during driving.

Many different companies such as industrial, automotive, engineering and medical sectors use DBB valves today. DBB valve selection can be challenging due to how multiple industries use these products for various purposes.

How to choose a Double Block and Bleed Valve

A Double Block and Bleed Valve is a valve that is used on pressure tanks to create two separate levels of pressure. It is used in water, gas, and oil pipelines to help maintain regulation over the flow of fluid.

Here are some factors you should consider when choosing a Double Block and Bleed Valve:

– Size – The size will need to accommodate the size of your pipe and tank so you don’t have any leakage issues with it.

– Material – You will want a material that can handle high pressures without compromising performance. This material needs to be efficient in the amount of heat it generates, which can be as high as 300-400 degrees Celsius


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