special connections and special joints in ducting including connections between ducting of differing materials, connections between ducting and equipment, isolated joints and flexible connections between ducting and plant, ducting turning, splitters and vanes, nozzle outlets, test holes and covers and access doors including forming and stiffening of openings, components for supporting ductwork including fixing, weathering aprons, flashing plates and the like, except where required to be measured separately, cowls and terminals. 2. Accessories for Ductwork 2.01 Weathering aprons, flashing plates and the like, when not included with the items to which they relate, are each given separately. 2.02 Each type of accessory is given separately. Dimensions are stated in descriptions. 2.03 Accessories are enumerated. 230519 METERS AND GAGES FOR HVAC PIPING 230523 GENERAL-DUTY VALVES FOR HVAC PIPING 232113 HYDRONIC PIPING 232300 REFRIGERANT PIPING 1. Pipework 1.01 Each kind of pipe is given separately, stating the Standard to which it complies. 1.02 Each diameter of pipe is given separately. Diameters stated are nominal diameters. 1.03 Pipes are given in metres measured the length over all fittings and branches.