In the case of O-rings the following principle is almost exemplary applicable: An ounce of prevention is worth a pound of cure (Benjamin Franklin). Why? Because the replacement costs for an O-ring are usually in significant disproportion to the amount of work in the repair.
Of course: complete quality checks are not for free! But please consider also the cost saving effects of a 100% quality check: internal time consuming quality checks before installing the O-rings and C-parts are obsolete; you thereby reduce the lead time in your internal production. Besides all that, you don't risk reputational damage by using unreliable O-rings in your high-end product!
Our experience of nearly 3 decades shows us that the quality inspection of O-rings and other C-parts almost always pays off! So: Do not hesitate to contact us!