Assembled view cut away section showing nipple in position.

Exploded view shows cross section of adjacent section parts and push nipple prior to assembly.

In modern high capacity sulfuric acid plants particularly in areas where cooling water conditions are severe, the elimination of most gasketed joints is desirable, to minimize the possibility of leaks which are recognized as the result of bolt corrosion. This corrosion eventually reduces the cross section area of the shank of the bolts holding sections together to a point where there is not enough metal to maintain the gasket seating stress. When this occurs, the affected bolts relax and cause a separation at the gasket which results in an acid leak.

The development of gasketless, permanent sealing joint provides a remedy for such conditions.

This closure is called push nipple joint, and consists of a mating machined surface in the section port to accommodate a finely machined cast iron cylindrical nipple. The nipples are ground slightly convex on the exterior, and the section surface is slightly tapered. When the joint is made up with the usual bolts drawing the adjacent sections together over the nipple, the nipple distorts sufficiently in compression to exert sufficient force against the section to provide a tight joint that no longer depends on the bolting for its integrity.

View of nipple showing details.

Assembly detail of push nipples and ports, dimensions shown are approximate.

Comparison with Shell and Tube H2SO4 Coolers
Design Features of Sections
Push Nipple Sections
Installation Advantages
Physical Characteristics
Type of Installations