by Robert L. Matthews
I always recommend reading the instructions in pump manuals and for the attachments like mechanical seals, secondary seals, braided packing, couplings, lubricators, descant breathers, and even how to install Teflon tape. Last week, I received a new set of labyrinth seals from AES Seal Co. (AESSEAL) that it provided for an aluminum training pump I’m building up. When I do pump, reliability, packing, seal and other training classes, I use all the samples I can to make the training real for the attendee. I use new and damaged items that tell the good and bad that we see each day. I have AES’ permission to use its instructions – read these carefully, this is good information and remember all reliable products come with similar instructions:
(i) Shaft Outside Diameter is within tolerance ±0.002" (±0.05mm).
(ii) Housing bore is nominal size ±0.001" (±0.025mm).
(iii) Shaft run out <0.010" (0.25mm) T.I.R. (Total Indicator Reading).
(iv) Shaft end float <0.010 (0.25mm).
(v) There are no sharp edges over which the seal ‘O’ Ring (2,8) and ‘O’ Ring (7) must pass. Break any sharp edges. Pay special attention to keyways, shaft steps and housing edges.
(vi) Clean and degrease the shaft and housing bore.
(vii) Lightly grease the shaft and shaft ‘O’ Ring (2,8) with lubricant provided. (P80 lubricant only)
(viii) Check that the ‘O’ Ring position sets on a unmarked area of the shaft.
(ix) Ensure shaft and housing surface finish is better than 32µ CLA (0.8µm Ra) at elastomer position 2, 7, & 8.
The following installation instructions may vary, depending on equipment configuration. Therefore use them as a guide line only.
- Press the LabTecta™ seal into the bearing housing plate. This plate is typically separate to the bearing housing. Note: Use a hydraulic press if available. The force from the press should be concentric to the plate bore. Avoid using grease on the housing. Always position outlet ports ‘X’ and ‘Y’ at the 6 o’clock position as shown.
- Slide the seal and housing plate assembly into the running position, on the shaft.
- Secure the housing plate into the bearing chamber.
- Assemble rest of equipment in final running position.
- Fill the bearing housing with an appropriate fluid, to the OEM/suppliers recommended fluid level.
- Spin the shaft by hand. Listen and feel for any shaft binding, etc.
Use the provided lubricant (P-80 ONLY) to grease the shaft and shaft ‘O’ Ring (2,8).
Don’t hit the seal. The outer housing is a slight interference fit with the nominal housing bore. If in doubt use a press to install the LabTecta™ into the equipment housing plate.
The following installation guide is applicable to all types of rotating equipment, however, is especially focused at PUMPS.
In AESSEAL© Experience, following this guideline will prolong your equipment life.
- LASER ALIGN SHAFT AND COUPLING
- USE SYNTHETIC BEARING LUBRICANT WHERE POSSIBLE; HOWEVER, CHECK THE SEALED FLUID COMPATIBILITY FIRST!
- FIT A CARTRIDGE SEAL AND SYSTEM
- ENSURE PUMP HYDRAULIC STABLE
- REMOVE ANY PIPE STRAIN
These instructions and more are available with this labyrinth seal. AES and other companies support reliability with their instructions. Please take time to thoroughly read and adhere to these instructions and improve your plant reliability.
About the Author: Reliability manager for Houston-based Royal Purple Ltd., Bob Matthews has 35-plus years of pump industry experience – from hands-on to supervision – in plant maintenance management, consulting and training. He has taught advanced pump classes for companies like Exxon, Phillips, Westinghouse as well as Auburn, University of Alaska, LSU, the Vibration Institute, ASME and FSA.