STRAINER

PURPOSE: To save a space for piping, lower installation costs and facilitate maintenance work without stopping the supply of fluid by integrally forming a flow passage switching mechanism for switching the flow passages so that the fluid can pass through or detour around a filter element. CONSTITUTION: A strainer 1 consists of a filter mechanism 2, an inlet part 3, an outlet part 4 and a flow passage switching mechanism 5. The flow passage switching mechanism 5 consists of a cylindrical flow passage switching rod 11 and a valve box 12 for clamping the flow passage switching valve rod 11. The flow passage switching valve rod 11 is provided with a passing flow passage 15 consisting of a communicating hole 13 communicating with the upstream side of a filter element 6 from the inlet part 3 and a communicating hole 14 communicating with the outlet part 4 from the downstream side of the filter element 6. In a position turned 90 deg. as shown by dotted lines, a detour flow passage 16 consisting of a communicating hole for making the inlet part 3 and the outlet part 4 communicate with each other is formed. By turning a flow passage changeover handle 17, either the passing flow passage 15 or the detour flow passage 16 is selected.