Single & Double Block and Bleed Valves | High-Pressure Isolation Valves

A block and bleed valve isolates an instrument or line from process pressure (the block) and then vents the trapped pressure (the bleed).

This lets technicians do maintenance, calibration or sampling safely. BuTech makes single block and bleed (SBB) and double block and bleed (DBB) needle valve assemblies for critical instrumentation in oil & gas, hydrogen and high-pressure industrial systems.

The range is built on six standardized valve styles. The goal is simple: easier configuration, shorter lead times and consistent ordering worldwide, with enough flexibility to fit very different system designs.

Six Standardized Block & Bleed Valve Styles

Single Block & Bleed Valves: One block valve and one bleed valve in a single body, for basic isolation, sampling and pressure verification.

Needle–Needle Valves: Needle valves for both isolation and venting, giving tight shut-off and controlled bleed-down.

Inline & Compact Single-Entry Valves: A space-saving design for crowded panels and tight installations.

Double Block & Bleed Valves: Two isolation barriers with a bleed valve between them, for redundant protection at critical points.

Ball–Needle Valves: Quarter-turn ball valve isolation combined with needle valve control for venting.

Multi-Instrument Manifolds: Isolation and venting for several instruments from one compact assembly.

SBB or DBB: Which One Do You Need?

Choose a single block and bleed valve for routine instrument isolation, gauge service, sampling and pressure checks.

Choose a double block and bleed valve when a single seal isn't enough, such as with hazardous fluids, high-pressure gases or any point where a leak past the block valve would put people or equipment at risk. The second barrier gives you redundant isolation, and the bleed between the two seals confirms that isolation is holding before anyone breaks a connection.

Browse by Type

Butech Double Block and Bleed Valves image

Block & Bleed Ball Valves

Reliable high-pressure isolation and venting, reducing leak paths and installation complexity with quarter-turn operation and pressure ratings up to 15,000 psi (1,034 bar).

Single & Double Block & Bleed Needle Valves

High-pressure assemblies for precise isolation, controlled venting, and pressure verification up to 60,000 psi (4,137 bar).

Why Use One Assembly Instead of Separate Valves?

When you replace separate valves, tubing and fittings with one block and bleed assembly, the installation improves in five ways:

Fewer leak points, because there are fewer threaded and fitted connections
Lower fugitive emissions, since every connection you remove is one less leak path
A smaller footprint, thanks to a compact design that frees up panel space
Faster installation, with fewer parts to fit, align and test
Less vibration stress, because a compact assembly carries less weight on the connections

Key Features

High-pressure designs for severe service
Redundant DBB isolation for critical applications
Precision needle valve control for stable flow and controlled venting
316/316L stainless steel, with specialty alloys available
NPT, MP/HP cone-and-thread and compression fitting connections
Hydrogen-compatible configurations available<

Applications

BuTech block and bleed valves are built for the small, high-pressure lines that measure, sample, test and dose a process.
At these points, technicians have to isolate the line, vent it and confirm it's at zero pressure before they touch a connection.

Oil & gas instrumentation panels

Isolate pressure transmitters, gauges and analyzers from the process, then bleed them down safely for calibration or replacement. On critical tie-in points, double block and bleed (DBB) configurations add a second isolation barrier.

Hydrogen compression, storage and dispensing

Hydrogen attacks standard materials through embrittlement. BuTech hydrogen valves are made from 316 stainless steel with at least 12.5% nickel to resist it. They're proven in hydrogen storage, compression and dispensing at pressures up to 20,000 psi (1,378 bar).

Pressure test benches and calibration equipment

Test rigs are connected and disconnected all day. A block and bleed valve lets the operator isolate the unit under test, vent the line and confirm zero pressure before every disconnect.

Chemical injection and sampling loops

The block valve isolates the line. The needle bleed valve then releases leftover pressure in a controlled way before a sample is taken or a line is opened. Specialty alloys are available for corrosive media.

CO₂ and carbon capture systems

Compact DBB ball valves rated to 15,000 psi replace multi-valve assemblies at CO₂ isolation points. This means fewer leak paths and a simpler installation.

Hazardous and high-pressure service

Some media are toxic, flammable or under extreme pressure, so a leak past one seal isn't acceptable. DBB valves give you two seals with a bleed port between them, which proves the isolation is holding. DBB needle valves are rated to 60,000 psi (4,137 bar) and DBB ball valves to 15,000 psi (1,034 bar), both at 72°F (22°C).

Industries served: oil & gas, hydrogen, petrochemical and chemical processing, power generation, research laboratories, aerospace and defense, industrial manufacturing and shipbuilding.

FAQ

A DBB valve combines two isolation valves with a bleed valve between them. Operators can vent the pressure trapped between the two seals and confirm isolation before starting work.

BuTech specialists are available to guide you in selecting the optimal DBB or SBB configuration for your high-pressure system. For engineering support, detailed specifications, or a formal quotation.

Single Block & Bleed and Double Block & Bleed Valves