Abstract: A valve assembly is constructed for use in a filtering system including a pump and a filter with an inlet and an outlet, for example those systems used in conjunction with swimming pools. The assembly includes a valve body with a pump inlet, a filtered output, a waste-water disposal outlet, a filter inlet, and a filter outlet. Pairs of a plurality of plunger heads are positioned within the valve body to provide a plurality of modes of operation, the pairs of plunger heads being positioned within the valve body in one of a filtering mode, a backwash mode, and a direct mode in which flow from the pump is directly into the waste-water disposal outlet. The pairs can be affixed on two different interchangeable plungers or moveably positioned on a single plunger.

Abstract: In a method of making an injectant-nonmetallic composite having a fracturable nonmetallic base material: a block of fracturable nonmetallic base material is encased in an investment material to an extent that the block is held together when fractured; the block is fractured; a bonding material is introduced into the fractures created in the block to bond the block together when the block is no longer encased in the investment material; the block is removed from the investment material and encased in a second investment material to an extent that the block is held together when the bonding material is removed from the fractures in the block; the bonding material is removed from the fractures in the block; the block is heated; and a molten injectant is introduced into the fractures and solidified to form an injectant-nonmetallic composite.