In manufacturing (and elsewhere), there are quality departments and various inspection stops along the production line. Some companies (such as Cross Pens) proudly tell you that they perform 100% inspection - meaning that every pen that leaves the factory has been looked over by the QC department. The more a company seeks perfection and zero defects, the more inspectors it needs. When business picks up, the company will need to hire even more inspectors. This method of ensuring that defect-free product goes out the door is very expensive indeed. You need extra people, you scrap material, a lot of work and parts go into a product that will never be sold, and the customer has to wait another day before the product can be shipped. Yet this was considered the only way to ensure excellent quality.
In the PVF business we tend to think of quality solely as a vendor issue. We inspect packages when they come in the door - not as they are going out. Thus we also tend to think that quality is the responsibility of the vendor. The supply house shouldn’t really have to check incoming valves or fittings for quality - the vendor shouldn’t be shipping us poor material. So, yes, of course it is your business to make sure you are dealing with reputable vendors. And I am sure that those of you who have recently ventured in the wild world of sourcing overseas make it a point to take a very hard look at that incoming material before sending it on to your customers.