Double Block & Bleed Valves
In high-stakes industrial environments, the safety of your personnel and the integrity of your process are non-negotiable. Kriloha Gaskets, a premier provider of high-performance sealing and flow control solutions, offers a robust range of Double Block and Bleed (DBB) Valves. As a flagship subcategory in our Valve and Fitting Accessories line, our DBB valves are engineered to provide absolute isolation in critical piping systems.
Catagories
What is a Double Block and Bleed Valve?
A Double Block and Bleed valve is an integrated system that provides dual isolation. According to API 6D, a DBB valve is a single valve with two seating surfaces that, in the closed position, provides a seal against pressure from both ends of the valve with a means of venting/bleeding the cavity between the seating surfaces.
The Anatomy of Safety:
Primary Block: The first upstream valve that stops the process flow.
Secondary Block: The downstream valve that acts as a redundant backup.
Bleed Function: A central vent valve used to drain or “bleed” any fluid trapped between the two blocks. This allows operators to verify that the primary seal is holding before performing maintenance.
Technical Specifications and Material Excellence
At Kriloha Gaskets, we treat every DBB valve as a safety-critical component. Our valves are manufactured from high-integrity forgings to withstand extreme pressures and temperatures.
Material Selection:
Stainless Steel 316/316L: Excellent for general industrial and chemical resistance.
Carbon Steel (A105/LF2): Ideal for oil and gas applications, including low-temperature service.
Duplex & Super Duplex Steel: Engineered for the highly corrosive environments of offshore platforms and desalination plants.
Specialty Alloys: Monel, Inconel, and Hastelloy options are available for specialized chemical processing involving aggressive media.
Design and Compliance:
Pressure Classes: Available from ASME Class 150 to 2500.
Fire Safe Certification: Designed and tested to API 607 and ISO 10497 standards.
Fugitive Emissions: Engineered to meet ISO 15848-1 standards, minimizing environmental impact.
Key Benefits of Integrated DBB Valves
Why should your facility move away from traditional “Valve Trees” toward Kriloha’s integrated DBB solutions?
1. Enhanced Personnel Safety
The DBB configuration provides a “verifiable” seal. By opening the bleed valve, a technician can confirm there is zero pressure leakage before opening a line, preventing accidental exposure to hazardous materials.
2. Significant Space and Weight Savings
Traditional double-isolation setups require two separate block valves, a T-junction, and a bleed valve, often spanning several feet. A Kriloha integrated DBB valve performs all these functions in a footprint only slightly larger than a single standard valve. This is critical for offshore rigs and modular skids.
3. Reduced Leak Paths
Every threaded or flanged connection in a piping system is a potential point of failure. By replacing a multi-component assembly with a single forged body, we reduce the number of potential leak paths by up to 60%.
Diverse Configurations for Every Application
Kriloha Gaskets provides DBB valves in various designs to suit specific flow characteristics:
Needle-Needle-Needle: Used primarily for instrumentation and small-bore piping where precision and space are paramount.
Ball-Needle-Ball: Combines the high-flow, quick-turn capability of ball valves for isolation with a needle valve for precise venting.
Full Bore Designs: Essential for lines that require “pigging” or where pressure drop must be kept to an absolute minimum.
Maintenance and Installation Guidelines
Mounting Orientation: While DBB valves are versatile, ensuring the bleed port is oriented for easy access and safe drainage is critical.
Sealing the Vent: Always use a secondary plug or “blind” on the bleed port when not in use to prevent atmospheric contamination.
Regular Cycling: For valves in critical safety positions, regular cycling (opening/closing) is recommended to ensure the seats remain free of debris and operational.
The Kriloha Edge: Integrated Sealing Expertise
We don’t just understand valves; we understand the Science of Sealing. Our DBB valves are designed to work seamlessly with our world-class Spiral Wound Gaskets and Kammprofile Gaskets.
When you choose Kriloha, you benefit from:
Anti-Blowout Stems: For maximum operator safety under high pressure.
Anti-Static Devices: Ensuring electrical continuity and preventing sparks in volatile environments.
Total Traceability: Every valve is laser-etched with heat numbers and supplied with full MTC (Material Test Certificates).
Available Profile Configurations
Frequently Asked Questions (FAQ's)
Q: What is the difference between DIB (Double Isolation and Bleed) and DBB?
A: A DBB valve seals against pressure from both ends of the valve. A DIB valve (Double Isolation and Bleed) provides two seating surfaces that each provide a seal against pressure from a single source. DIB is often preferred for more critical “Double Block” requirements where one seat must provide a backup for the other from the same direction.
Q: Can Kriloha DBB valves be used for "Lethal Service"?
A: Yes. For lethal or highly toxic service, we offer specialized bellows-sealed or double-packed DBB valves that meet the most stringent leakage requirements of ASME B31.3.
Q: Are these valves suitable for sour gas (H2S)?
A:Absolutely. We offer NACE MR0175 / ISO 15156 compliant DBB valves using hardness-controlled materials to prevent sulfide stress cracking.
Q: What is the standard end connection for these valves?
A: We offer a wide variety, including Flanged (RF, RTJ), Threaded (NPT, BSPT), and Socket Weld ends to match your existing piping.
Q: How do I verify if the primary seal is leaking?
A: With the two block valves closed, open the bleed valve. If fluid or gas continues to flow steadily from the bleed port after the initial cavity pressure is released, it indicates that the upstream block seat requires maintenance.
Contact Kriloha Ltd. Today
for your valve and fitting parts accessories requirements. Invincible Seals. Agile Solutions.