InTheField
Mechanical
Ok, I know this is a long shot, but here it goes. I have an old howden ID fan on a power boiler (biomass) that has seen its fair share of erosion. The impeller to hub bolts are still in decent condition, however we are looking at having to replace the nuts. I am a fairly seasoned and experienced fiend service engineer with OEM experience. I have contacted the OEM on a long shot - no info. I am waiting on a response from Howden (no call back yet and I doubt they have the info from 1970).
I am thinking these are zero clearance bolts - shrink fit. They appear to be 1 - 1-1/4" diameter. Any thoughts as to material - my guess would be an ASTM A325 structural bolt. We are doing PMI on the bolts, nuts and hub tomorrow. I do not think we have a 4140 shaft or hub in this application.
Any thoughts appreciated! We are covering the nuts and bolts after with pipe caps with a chromium carbide overlay.
I am thinking these are zero clearance bolts - shrink fit. They appear to be 1 - 1-1/4" diameter. Any thoughts as to material - my guess would be an ASTM A325 structural bolt. We are doing PMI on the bolts, nuts and hub tomorrow. I do not think we have a 4140 shaft or hub in this application.
Any thoughts appreciated! We are covering the nuts and bolts after with pipe caps with a chromium carbide overlay.