BS 8561:2021 pdf download

BS 8561:2021 pdf download.Specification for mechanical fittings for use in the repair, connection and renovation of pressurized water supply pipelines — Requirements and test methods
1 Scope
This British Standard specifies the requirements and associated test methods for mechanical fittings intended to: .
a] join polyethylene pressure pipes with an aluminium barrier layer for the supply of cold potable water for installation in contaminated land;
b] join new water supply pipes to existing water supply pipes for the purposes of repair, branch connections or pipeline renovation; and
c] repair existing water supply pipes.
It also specifies requirements for materials and dimensions and mechanical properties for mechanical fittings.
It applies to fittings:
1) in the diameter range of DN 50 to DN 1 200 made for use on grey iron; ductile iron; steel; or polyvinyl chloride (PVC-U, PVC-0); .
2) in the diameter range of DN 63 to DN 1 000 made for use on polyethylene pipe; and
3) in the diameter range DN 63 to DN 630 made for use on polyethylene barrier pipe.
NOTE Fittings are not made or tested for use on fibre cement and glass-reinforced polyester (GRP) pipes. Where there is a requirement for connection to existing pipework from these materials, advice may be sought from a fitting manufacturer.
3 Terms and definitions
For the purposes of this British Standard, the following terms and definitions apply.
3.1 mechanical fitting
fitting which includes one or more compression zones to provide a leaktight seal on a pipe, between pipes, and a fitting .
3.2 joint
mechanism within a mechanical fitting that provides a leaktight connection between a fitting and a pipe or between fittings
3.3 flexible joint
joint that permits significant angular deflection between the pipe and the fitting both during and after installation
3.4 end load resistant joint
joint capable of resisting the end load transmitted via a connecting pipe and generated by internal pressure, pipeline external interference, and thermally induced stress, in any combination
3.5 dedicated coupling
mechanical fitting providing connection between two pipe spigot ends of the same outside diameter
NOTE A dedicated coupling would typically connect pipes of the same material together:
3.6 dedicated stepped coupling
mechanical ftting providing connection between two pipe spigot ends of different outside diameter
NOTE A dedicated stepped coupling would typically connect two different pipe materials together: Also known as a dedicated reducing coupling.
3.7 wide tolerance coupling
mechanical ftting capable of connecting a range of pipe materials and/ or pipe dimensions providing connection between two pipe spigot ends
3.8 wide tolerance step coupling
mechanical ftting capable of connecting a range of pipe materials and/or pipe dimensions providing connection between two pipe spigot ends of different outside diameter