Why is so hard to find a good valve supplier in China

Everyone knows China is the biggest amount of valve factories in the world, there are total more than 6,000 factories. they mainly distributed in three province of China:
1- Tianjin Province, the factories located here mostly focus to produce rubber lined valves with body material cast iron or ductile iron.
2- Suzhou Province, the factories located here mostly focus to produce big size, high pressure, and some high challenge valves, that’s why the top 3 valve’s factory all located in this province, such as Neway Valve, SUFA Valve.
3- Zhejiang Province, the factories located here mostly focus to produce standard valves, mainly produce GGC valves, Metal seated butterfly valves, floating and trunnion mounted ball valves, sleeve type plug valve, Teflon plastic lined valves, normally foundry located here supply carbon steel and stainless steel more than other materials.
Though you can find valve producer very easy, but it’s still very hard to decide who can be your supplier. One of the biggest reason is when customer browse supplier’s website, customer will find most of factory can produce many types of valves, the worse thing they use the same valve pictures show in website. That will confuse customer to judge who is the real producer.
So when customer want to place order on one Chinese valve producer, they always need to fly almost 10 hours to China to visit factory first. Because sometimes customer feels disappoint after they visited factory, the fact of factory is so much difference then imagine. It’s not only waste customer’s money also time.
If you also face these problems, that’s better one 3rd party who can help you to solve.