The John wafer type tilting disc check valve, Fig. 4205 is an economical alternative to the conventional type tilting disc valve. The overall length of the body has been reduced to the extent that in the fully open position, the disc extends into the pipeline.
This considerable reduction in size and weight greatly facilitates installation and reduces installation costs. The disc swings on large diameter hinge pins and a high degree of pressure tightness is assured by the slight clearance on the pivots permitting the disc, when closed, to be completely unsupported by other than the seating face.
