Discussion Overview
The discussion centers around the design of a mechanical seal for a remotely operated vehicle (ROV) thruster intended for use in both salt and fresh water at depths of up to 100 meters. Participants explore various types of seals, materials, and design considerations relevant to ensuring effective sealing under these conditions.
Discussion Character
- Technical explanation
- Exploratory
- Debate/contested
Main Points Raised
- Bill Black seeks resources for selecting a mechanical seal for a propeller shaft in an ROV thruster, emphasizing cost-effectiveness and design challenges.
- Some participants suggest considering Chicago Rawhide's lip seals, noting that the effectiveness depends on shaft diameter and surface speed, and express concern about pressure differentials across the seal.
- One participant requests additional information about the seal type, pressure differential, rotational velocity, dimensions, and fluids involved to better determine suitable seal options.
- Another participant mentions the use of graphite-faced mechanical seals and discusses the need for a variable loading system on bellows to accommodate pressure changes with depth.
- Bill Black provides specific design parameters, including a .375 polished 303 stainless steel shaft and a maximum RPM of 1000, while expressing concerns about the cost of Teflon seals.
- Concerns are raised about the suitability of lip seals for the application, particularly regarding their vulnerability to radial play and the need for a clean, polished surface for effective sealing.
- Some participants suggest using O-rings as a cost-effective sealing solution for limited use, while others recommend more robust seals for extended underwater operations.
Areas of Agreement / Disagreement
Participants express a range of views on the best type of seal for the application, with no consensus reached. There are differing opinions on the effectiveness of lip seals versus O-rings and other seal types, as well as concerns about pressure handling and material choices.
Contextual Notes
Participants highlight various assumptions, such as the pressure differential and the need for specific seal characteristics based on the ROV's operational parameters. The discussion includes unresolved questions about the best materials and designs for the intended use.