Technical Knowledge

This article lists five parameter gaps that keep repeating on pump OEM seal spec sheets: missed stuffing box geometry, pressure transients, seal chamber temperature, face peripheral velocity, and trace fluid contaminants. None calls for a different seal model; each needs the right number on the spec, and FBU builds cartridge seals across the API 682 arrangements for pump OEM programs.   Read More>

This article frames mechanical seal selection as one chain from pump to medium: the pump sets the stuffing box, then pressure sets single or double, temperature sets the elastomer and balanced face, the fluid sets materials, speed sets peripheral velocity, and the flush plan is chosen with the seal. It covers practical points such as ANSI B73 / Sulzer APP, API 682 arrangements 1/2/3, SiC and TC pairings, and Plan 11/21/32/52/53/54. The takeaway is that no single number picks the seal; the final limits live on the data sheet for the exact model.   Read More>

A pump running two different fluids does not automatically mean a seal change. The seal only meets the process at a short list of wetted parts: faces, elastomer, and metal hardware. Compatibility is judged part by part. The elastomer is the usual weak point, since SiC, tungsten carbide, and 316 hardware resist most chemicals that destroy rubber. When both fluids fall inside the same material envelope, the seal stays. When one fluid leaves that envelope, the elastomer or the whole seal changes. Temperature follows the hotter service, and residual fluid left in the stuffing box can react with the next fluid, so a chamber flush between services matters. A double seal shifts the question to the barrier fluid.   Read More>

A removed mechanical seal that smells burnt has overheated at the faces. The smell comes from the elastomer, not the metal. Heat is generated by friction between the rotating and stationary faces once the lubricating fluid film is lost. The three usual causes are dry running, flush system failure, and installation error. A blue or rainbow tint on the carbon face signals oxidation. Diagnosis starts with the faces, then picks the elastomer by the temperature the faces actually reach, not the nameplate figure.   Read More>

A mechanical seal's metal parts, the sleeve, gland and springs, ship as 316 stainless by default. See the rule for when upgrading to duplex 2205 pays on a rebuild, when 316 stays the call, and why the spring often needs a better alloy than the sleeve.   Read More>