vacuum ports

Self-sealing vacuum ports in combination with a Deck Purge Box ease the procedure to open and close pressure housings and eliminate any moisture inside the enclosure.


Instrument housings usually incorporate a vacuum port to facilitate repeated sealing and unsealing actions.

Nautilus Marine Service offers manually locking and self-locking vacuum ports.

For both types two versions are available. Manually locking vacuum ports can be supplied with a single or double o-ring seal and self-locking vacuum ports with either 7/16” or 5mm shaft diameter.

Self-locking vacuum ports together with the VITROVEX® Deck Purge Box is an innovative locking and purge concept and provide immediate improvement over traditional, manually locking vacuum ports by dynamically removing moisture from the entrained air inside an instrument housing.


Please follow below for more details.

Additional information
Part numberPrevious part numbersIllustrationDescription
NMS-VP790260Manually locking vacuum port with single o-ring seal
Application is limited to enclosure with max. 14mm wall size
NMS-VPL790260LManually locking vacuum port with double o-ring seal
Suitable for all VITROVEX glass enclosures
NMS-VPSNMS-IS-CON10Self-locking vacuum port is a component of an innovative locking and purge concept, requiring a custom purge fitting (P/N VPS-HA) or VITROVEX deck purge box (P/N NMS-DPB) to interface to any vacuum purging system.
NMS-VPRNMS-IS-CON11retrofit version of NMS-VPS to assure backward compatibility with earlier VITROVEX® and other vacuum fittings.
VPS-HAHose adaptor for self-locking vacuum ports

Often the questions arise regarding the difference between the glass-to-glass interface at the equator, and the metal-to-glass interface at the feed-through, and why grease is appropriate for one and not the other. The difference is that one can cut an o-ring groove in the metal.  Doing this in glass is much more difficult and there is a risk of fracturing if the stresses are not uniform, hence a bare-naked glass to glass interface with an external sealing band is the way to go on the glass enclosures.

For vacuum ports however, a small amount of grease to lubricate the o-rings is important.  Without it they can easily get small tears or suffer abrasion and may not slide into place easily when pressurized.  Applying more than a thin film of grease confers no advantage but adds the risk of collecting dirt and debris.


Please also refer to our guidelines for the installation of vacuum ports in the download section.

Data sheet self-sealing vacuum ports
Data sheet VITROVEX deck purge box
General arrangement drawing NMS-VP
Installation guidelines  for NMS-VP, NMS-VPL