Strainer baskets are made of perforated sheet metal and a wide range of opening sizes is available. The size of the basket perforation should be slightly smaller than the minimum particle size to be removed. Using a smaller perforation opening than necessary only means the basket will fill and clog more quickly and have to be cleaned more often. Well made strainer baskets should be brazed or welded. The use of solder to hold the basket together cuts the cost, but it is not recommended.
Soldered baskets are inherently weak and can break easily.
I f finer straining is needed, then the gasket is fitted with a wire mesh liner inside the perforated sheet. Here the mesh lining does the actual straining, while the outer metal sheet acts only as a mechanical support. This gives the best combination of maximum flow rate with the least loss of strength. It is important that the wire mesh be integrally and tightly fastened at the tip and bottom of the basket, other wise material can bypass the mesh lining by getting behind or under it. For this reason baskets with removable mesh lining should be avoided.