How to identify imported pneumatic valve

the first one is the factory has been proved that most of foreign manufacturers will issue a certificate of a piece of this product conforms to the requirements of the factory, there could be the signature of the director general, sometimes the factory showed that looks more like a piece of invoice.
the second is to test proves that the pneumatic valves or fittings factory some will have the same product testing report ( 测试认证) , it provides a series of test parameters, they'll charge you extra for some factory inspection report.
the third is the country of origin certificate ( 原产地证书) , proved to be issued by chamber of commerce of origin certificate of origin, is the charge.
the fourth is the customs declaration, bulk cargo import will have a customs declaration form, the above shows the information such as country of origin, the importer, can prove that the source of the product. Small products, if walk fast customs clearance, there is no customs declaration.
if the product has come to hand, the plate if there is a serial number, you can directly contact the factory or office to identify the authenticity of the product. Is important when purchasing will probably understand the value of the product, can't pursue cheap, pure go office or agency purchase price will be higher, but the guarantee is the real thing, the premise is you can actually find formal agent, rather than on the baidu promotion said he is the agent.
there are a few small traders, they will bypass the domestic office procurement, so that the price will be down, but the current domestic dealer the good and bad are intermingled, lack of effective supervision, really fake goods is difficult to identify, compare several more, don't choose the price is too low, definitely choose worked right!