Zhejiang Dream Industry Limited
Plugs Caps,Plastic Protective Cap Plug,Cap Bottle Plug,Rubber Cap Plug
Core Plugs Caps are used to fill the sand casting core holes found on water-cooled internal combustion engines. They are also commonly called frost plugs, freeze plugs, or engine block expansion plugs.
The Welch plug, (misnomer: Welsh plug), is a thin, domed disc, of a metallic alloy, which is pressed, convex side out, into a casting hole and against an internal shoulder. Alternatively a non-ferrous metal such as brass offers improved corrosion prevention. When struck with a hammer, the dome collapses slightly, expanding it laterally to seal the hole. Other core plugs have a dish design, so that when pressed into the casting hole the tapered sides form the seal.