  Using supersymmetric localization, we consider four-dimensional
$\mathcal{N}=2$ superconformal quiver gauge theories obtained from
$\mathbb{Z}_n$ orbifolds of $\mathcal{N}=4$ Super Yang-Mills theory in the
large $N$ limit at weak coupling. In particular, we show that: 1) The partition
function for arbitrary couplings can be constructed in terms of universal
building blocks. 2) It can be computed in perturbation series, which converges
uniformly for $|\lambda_I|<\pi^2$, where $\lambda_I$ are the 't Hooft coupling
of the gauge groups. 3) The perturbation series for two-point functions can be
explicitly computed to arbitrary orders. There is no universal effective
coupling by which one can express them in terms of correlators of the
$\mathcal{N}=4$ theory. 4) One can define twisted and untwisted sector
operators. At the perturbative orbifold point, when all the couplings are the
same, the correlators of untwisted sector operators coincide with those of
$\mathcal{N}=4$ Super Yang-Mills theory. In the twisted sector, we find
remarkable cancellations of a certain number of planar loops, determined by the
conformal dimension of the operator.
