Infrastructure Australia has confirmed that it is mandatory for a coupling to have a certified D-value and V-value if it is towing a rigid-drawbar (pig) trailer weighing more than 3.5 tonne. An advised maximum resting draw bar weight is an S-value and it cannot be substituted for a V-value. Couplings rated above 3.5 tonne must be marked with their D and V-values.
The 5 tonne rated Hitch-Ezy has a D-value of 30.2 kN, V-value of 16.1kN and the resting draw bar weight (S-value) during the 2 million cycle dynamic testing (performed by Hayman Reese's Horizon Global division) with horizontal and vertical rams acting simultaneously but out of synchrony was 500kg. Not all couplings promoted as suitable for towing above 3.5 tonne have a marked V-value and presumably have not undergone the requisite dynamic two-axis testing just described. Failure to comply with Australian Design Rule 62/02 might result in an insurer denying liability.
The Component Registration Number (CRN) for the 5 tonne Hitch-Ezy is 47868 and for the 3.5 tonne model the CRN is 47869; both couplings are thus suitable for original equipment manufacture.