BS EN 74-2:2008 pdf free.Couplers, spigot pinsand baseplates foruse in falsework andscaffolds Special couplers—Requirements and test procedures.
BS EN 74-2 lt gives recommendations for on-going production control.
These couplers are for use principally in temporary works.Each coupler is able to be fixed to at least one sideto one 48,3 mm diameter steel or aluminium tube. For the other side of reduction couplers，this standardspecifies requirements for the diameter and wall thickness of tubes.
For testing, screw couplers are tightened with a torque of 50 Nm and wedge couplers are tightened with a500 g hammer until the jarring blow.
Other special half couplers such as half couplers attached by riveting，used mainly for members ofprefabricated scaffolds, are outside the scope of this European Standard.
NOTE lnformation on design using special couplers is given in Annex B.
The following referenced documents are indispensable for the application of this document. For datedreferences，only the edition cited applies. For undated references， the latest edition of the referenceddocument (including any amendments) applies.
EN 74-1:2005, Couplers, spigot pins and baseplates for use in falsework and scaffolds — Part 1:Couplers fortubes—Requirements and test procedures
EN 1090-2:2008,Execution of steel structures and aluminium structures — Part 2:Technical requirements forsteel structures
EN 12811-1:2003，Temporary works equipment— Part 1: Scaffolds — Performance requirements andgeneral design
EN 12811-2:2004,Temporary works equipment — Part 2: Information on materialsEN 12811-3:2002,Temporary works equipment – Part 3: Load testing
EN ISO 898-1:1999, Mechanical properties of fasteners made of carbon steel and alloy steel — Part 1: Bolts,screws and studs (Iso 898-1:1999).
For the purposes of this document,the terms and definitions given in EN 12811-1:2003 and EN74-1:2005and the following apply.
half coupler (HW, HT) coupler which connects a tube of 48,3 mm diameter to another member either by means of welding (HW)orby means of a welded-in threaded element (HT).
In general a connection between two members is able to transmit three internal forces and three moments atright angle.There are related stiffnesses.
The connection of a tube to another member by a threaded element fixed half coupler (HT) or by weldable halcoupler (HW) is designed to transmit three forces. Additionally,Class B half coupler connected by awelded-in threaded element (HT) is designed to transmit one bending moment and a Class B screw weldablehalf coupler (HW) is designed to transmit two bending moments as listed in Table 3. BS EN 74-2 pdf download.