A Double Block and Bleed (DBB) valve is a combination of two isolation valves placed back-to-back and a third bleed valve in the center cavity.
These valves are used to segregate two pressure sources and to bleed, vent or introduce pressurized media in the void between the two sealing elements. They can be found in many different industries and applications, such as gas and liquid pipelines, production, processing, instrumentation and more, and are used for the following:
Note that the term DBB valve should not be confused with the term Double Isolation and Bleed (DIB) valve, which is defined by API 6D as a “single valve with two seating surfaces, each of which, in the closed position, provides a seal against pressure from a single source, with a means of venting/bleeding the cavity between the seating surfaces. The note adds that this feature can be provided in one or in both directions.”
Habonim offers an enhanced and comprehensive DBB valve offering that comprises two in-line floating ball vales and one bleed valve (can be a floating ball valve or a needle valve). These valves offer three major benefits:
There are many advantages to using casted-ready valve components. Cast valve designs offer flexibility as it enables us to create valves from different materials and with complex shapes, patterns and sizes, as well as different configurations to suit specific requirements that are utilizing stocked parts of our standard offering. For example, our casts are made so that actuators can be easily connected in any line configuration. In addition, casting is a more cost-effective solution as it eliminates material waste, can be used to reproduce valve series with more complex or large parts, reduce the amount of labor required for forging valves and machining costs, and makes it easier and less time-consuming to make replacement valves when required.
Our DBB valves are equipped with the Total HermetiX integrity package, which includes a double-body sealing for body-to-ends and for body-to-bonnet superior atmospheric sealing, the patented HermetiX™ steam sealing with zero fugitive emission sealing capability, which is tested and certified to ISO 15848-1 and API641 standards with up to 500,000 maintenance-free cycles life span. In addition, its fully fire-safe tested and certified design meets API 607 and ISO 10497 standards.
Based on Habonim’s proven standard parts and existing valve series for proven reliability and performance
Our DBB valves are based on the following existing and proven series, which means higher reliability, availability and cost-efficiency:
This Double Block and Bleed (DBB) valve is based on our 47 3-piece series for a size range of 1/4”- 2 1/2” (DN8-DN65) and Class 600 pressure rating with a variety of optional end connection styles. It incorporates two main isolation valves and one bleed valve in a single body construction, and offers the lowest possible number of potential leakage points with a reduced overall system size and weight, and the integrity of the Total HERMETIXTM package.
This unique casted Double Block and Bleed valve offering completes our already-comprehensive offering of trunnion mounted ball valves, BAR-made valves, “wafer” style valves, special alloy, and custom-made valves – all of which are now available in DBB designs that answer the diverse range of industrial requirements for cryogenic, high-pressure, high-temperature, and other applications.
Learn more about our casted DBB 3 piece floating ball valve based on our 47-series here and our 73-series here.
Our top quality valves are In Stock & Ready For Delivery at the right price.
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