All bolts behave like a heavy spring. As you turn down the nut against the flange, the bolt stretches and the flange and gasket compress. All bolt-tightening methods result in stretching the bolt. The torque-tightening method uses the thread helix of turning the nut against the reactive forces of the flange to stretch the bolt. The hydraulic bolt-tensioning method utilizes an annular piston threaded on the end of the bolt to provide an axial stretch.http://www.yuchaobolt.com/bolt/carriage-bolt/

Another indispensible equipment is steel pipe printing marking machine. Companies that produce metal pipes, regardless of whether they are involved in construction, aerospace, electronics, etc., code these materials to enable traceability, display important production data, and prevent counterfeiting. These codes generally take the form of numeric lot numbers or machine-scannable bar codes.http://www.westwu-machine.com/....pipe-spray-painting-

The way a ball valve functions makes it easy to see if the valve is open or shut. The handle that operators use to adjust where the sphere is aligned with the flow when the valve is open, and it is perpendicular when the valve is closed. And the ball valve can be devided into many different types for different functions, such as floating ball valve, trunnion mounted ball valve, top entry ball valve, dbb ball valve, subsea ball valve, etc.
http://www.tfcvalve.com/butterfly-valve/

One of my mantras as a crafter and a product reviewer is "There is no BAD products- only finding the right one for the job at hand." And by and large, that is true. The only time when you really need to know "which is better than that" is when you have multiple choices in the same product category.
http://www.subbuteo.com.cn/main-products/

These are the vital substances used for the production of active ingredient used in the formulation of pesticide. Thus, extensive demand for agricultural products drives the global pesticide intermediate market. Further, increase in global population and food demand boosts the market growth. However, stringent regulations associated with the production and usage of pesticide intermediate restrain the market growth during the forecast period. http://www.purestchem.com/pest....icides-and-pesticide