Sandvik 152 357 98 Diaphragm

The diaphragm, part 152 357 98, is a thin flexible membrane that moves with every pressure pulse in the circuit it serves, which makes it a fatigue part more than a wear part. Each stroke flexes it at the same fold line, and over a very large number of cycles the rubber or elastomer begins to craze there, so the diaphragm may look fine from one side and still be close to failing along that fold.

Fluid compatibility matters as much as cycle count, because an elastomer that swells or hardens in the wrong oil or at the wrong temperature loses its flex life far sooner than it would in the fluid it was selected for. Inspect the fold area for fine cracks, flattened sections or a permanent set that stops the membrane returning to its shape, and replace it before it tears and lets one side of the circuit contaminate the other. Quoting by the exact part number matters here, as diaphragms of similar outline can differ in thickness and material. Stalroc quotes this Sandvik reference by part number and exports worldwide to mining, quarrying, and drilling contractors.