On a live pipeline or process line, safe isolation is never assumed. You need to be able to prove it – positively, and on demand. That’s what Colson’s pipeline double block & bleed (DBB) valves are built to deliver: positive double isolation with a central bleed, in a single, robust, fire-safe tested assembly.
Colson’s modular DBB ball valves are engineered for pipeline and process isolation duties where safety, compliance and verifiable isolation are essential. Every valve is designed and manufactured in-house at our Rotherham facility.
What double block & bleed gives you
Double block & bleed brings two isolation points and a bleed together in one body. The two ‘blocks’ seal off flow from either side, while the central bleed vents the cavity between them. Bleeding that cavity lets an operator confirm both seals are holding, giving verifiable isolation before any downstream work begins. (For the full explainer on how DBB isolation works, see our guide: What is a double block and bleed valve?)
A single DBB valve also takes the place of multiple separate valves, along with the spool pieces, flanges and potential leak paths between them. That means a more compact installation, fewer connections to maintain, and a lighter footprint at maintenance and sampling points – with proven isolation built in.
The Colson pipeline range
The pipeline range provides positive double isolation with a central bleed, in a robust, fire-safe tested design. It’s available across a wide span of flange sizes, pressure classes and materials, in Ball/Needle/Ball or Ball/Ball/Ball configurations to suit different isolation requirements.
Fire-safe tested to ISO 10497, with full material traceability and compliance with internationally recognised standards, the range is specified where isolation integrity is non-negotiable.
Explore the series:
Typical applications
Colson pipeline DBB valves are commonly specified in:
- Pipeline isolation
- Process isolation and maintenance points
- Fugitive emissions control
- Safety-critical isolation duties
Compliance and traceability
All products are manufactured under ISO 9001 certified quality management systems. Full material certification is supplied as standard, with traceability maintained from source material throughout the manufacturing process. Inspection and test records are available to support audit, third-party witnessing and asset management requirements.
More on the standards behind every valve is set out in Colson’s quality, compliance and certification information.
Talk to the team
For sizing, configuration or material selection on a pipeline or process isolation duty, get in touch with the Colson Valves team.