Technical downloads
Installation manual, data sheets and certification.
Current Flexigas CSST documents for installers, merchants and specifiers: the UK installation manual, standard CSST specification sheet, BSI Kitemark certificate, brochures, sizing tools and DS support documents where applicable.
Data sheets
Standard Flexigas CSST specs.
Use these documents for the standard Flexigas CSST system. Flexigas current production uses 316L stainless steel tubing, is certified to BS EN 15266:2007 under BSI Kitemark KM 598726, is rated MOP 0.5 bar and covers DN15 to DN50.
-
Download
Standard Flexigas CSST Spec Sheet
Sizes, dimensions, materials and working parameters for the standard Flexigas CSST tubing and fitting system.
View the product range or ask technical support.
PDF
Installation
On-site reference.
-
Download PDF
UK Installation Manual
The current Flexigas UK installation manual. Cuts, terminations, routing, bonding, testing, sizing context and standards for Gas Safe registered engineers.
Read the HTML guide or open the retained guide page.
PDF
The retained installation manual PDF URL now serves the current 2026 manual, preserving existing search demand while giving installers the current document.
DS support
DS documents are support-led.
Flexigas DS is in transition. Existing DS documents remain available for installed-base and support context, but current DS availability, document status and project suitability should be checked with Flexigas technical support before use on a new job.
-
Open PDF
Flexigas DS Double Sleeve Data Sheet
Legacy DS double-sleeve data sheet retained for support context while DS is in transition. Confirm current availability and guidance before specifying.
Read DS support guidance or contact technical support.
DS PDF
Certifications
Approvals and certification.
-
Download
BSI Kitemark Certificate
BSI Kitemark KM 598726, certified to EN 15266. For building control and specification.
PDF
Tools
Size it in your browser.
The gas pipe sizing calculator sizes a run on site, free, with no app to install. It works in your phone browser and updates as you type.
-
Open the calculator
Gas pipe sizing calculator
Size Flexigas runs on site to BS 6891. Free, in your browser, with a live result.
In-browser tool
Need something else?
Can't find the document you need?
Talk to the Flexigas technical team and we will send it over, or answer your question direct.