Re: Thru hull seals

[John Brownlee <jonnie@chronic.lpl.arizona.edu>]

	Hello everyone, first-time poster and hopefully not raising
anyone's ire by responding.
	This question actually relates to one of my own. Briefly, I am
trying to calculate the failure pressure for a stuffing box of my own
design. I do not mean the structure itself, i.e. the flange-hull mount is
not the subject of this calculation, but rather how much stuffing is
required to seal against a known hydrostatic pressure. If the shaft
through the box is stationary, this is a simple viscosity problem but it
is moving. I'm not sure how best to treat the motion of a control or drive
shaft in this seal. Also, some stuffing is lost over time in operating the
shaft through the stuffing box. Anyone have a good reference on estimating
the loss per linear or radial distance the control rod is moved through?
	Any thoughts on how to set up this analysis? I've got an
engineering background, but not a maritime one specifically. Thanks for
your ideas or references,

							John

John Brownlee
Lunar and Planetary Lab
University of Arizona
jonnie @ lpl . arizona . edu