Patent ID: 7882978

Claim:
A threaded channel closure for a tubular heat exchanger comprising: a channel header wherein a gasket is provided at a shoulder of a channel, a tongue of a diaphragm is provided to apply pressure on the gasket to achieve a sealed joint, an outer compression ring is provided at a back side of the diaphragm and being loaded by push bolts provided at a periphery of a threaded lock ring, the outer compression ring being supported by a channel cover, which is kept in position by the threaded lock ring, wherein: the channel header is provided with a first plurality of radial holes on a periphery of the channel header, approximately at a centerline of a width of the outer compression ring in an assembled condition; the outer compression ring being provided with a second plurality of radial holes matching the first plurality of radial holes in number as well as angular position; the channel cover being provided with a set of blind holes matching with the first plurality of radial holes and hence also with the second plurality of radial holes; a plurality of threaded holding pins being provided to engage with the first and second plurality of radial holes and the blind holes together with adjusting nuts provided on a threaded portion of the threaded holding pins; a plurality of cleats being fixed on the channel header adjacent to the first plurality of radial holes and being arranged such that the threaded holding pins can easily pass therethrough, while a radial movement of the nuts is restricted by the cleats; a first plurality of feed holes being provided in the threaded lock ring so as to feed lubricating fluid to a threaded push bolt and to a threaded joint between the threaded lock ring and the channel header; a second plurality of feed holes being provided to feed lubricating fluid to an inner push bolt; an outer diameter of the channel cover mating with the threaded lock ring being provided with close tolerance to achieve a location fit for a first small length of approximately 10 mm to 100 mm and for a second small length, followed by a tapered diameter portion and a remainder of the diameter of the channel cover being provided with liberal clearance; and a guide ring being fitted with threaded fasteners at an end of the channel header, an inner diameter of the guide ring being provided with close tolerance to achieve a mating fit to the outer diameter of the threaded lock ring, thus the threaded lock ring is supported accurately concentric at an inner end and an outer end.