Name: Subsea M8 Vent & Vacuum Plug
Brand: Blu-Sub
SKU: BS-SSC-ENCLV-BLK-08A1
Price: 29.95 CAD
Availability: InStock

$29.95

28 Units Available for Quick Ship - Ships in 1-2 Business Days

Additional Units Made to Order - Ships in 2-4 Weeks

HS 8481.80 (CN)

Shipping calculated at checkout.

Type

M8 Enclosure Vent

Vacuum Plug

The Subsea M8 Vent & Vacuum Plug is a compact and modular solution designed for pressure equalization, enclosure disassembly, and basic vacuum leak testing of subsea housings. It works in tandem with the M8 Enclosure Vent, forming a two-part system—both components are sold separately.

This plug allows temporary connection to a vacuum pump (not included) to perform quick vacuum leak tests. Once the hose is removed, the system does not self-seal—so the vent must be manually sealed by screwing in the M8 Vacuum Plug. This makes it ideal for users needing basic airtightness checks, but not continuous vacuum retention.

For users who need to maintain vacuum pressure after testing or want a dual-purpose self-sealing port, the Subsea M10 Self-Sealing Vent & Vacuum Plug is the preferred option. The M10 version includes a lock cap and internal valve for more advanced use cases.

The M8 system is best suited for users prioritizing space savings and manual venting functionality during enclosure servicing or flange removal. A compatible vacuum pump with a 5 mm ID hose is required for testing but is not included.

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Material	Aluminum + Stainless Steel (Vent), Copper (Vacuum Plug)
Weight	12g Enclosure Vent / 13g Vacuum Plug
Color	Stainless Steel Plug, Black Bulkhead, Copper Vacuum Plug
Depth Rating	1,000 m / 3,280 ft
Dimensions	Refer to dimension drawing

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Description

The Subsea M8 Vent & Vacuum Plug is a compact, dual-purpose component designed for watertight subsea enclosures. It enables both passive venting for pressure equalization and manual vacuum leak testing. This system consists of two separate components: the M8 Enclosure Vent and the M8 Enclosure Vent Vacuum Plug, which are sold separately.

During vacuum testing, the plug accepts a hose with a 5 mm inner diameter (ID) and 8 mm outer diameter (OD). It does not self-seal—air re-enters the enclosure immediately after the hose is removed. A compatible manual vacuum pump is required for testing but is not included. After testing, the stainless-steel hex plug is installed to seal the port, providing a watertight seal rated for 1,000 m / 3,280 ft. A built-in stainless mesh prevents particles from entering the enclosure.

For applications that require vacuum to be maintained after testing, or when a single port is needed for both vacuum and vent functions, consider the Subsea M10 Self-Sealing Vent & Vacuum Plug. It features an internal valve and lock cap that allows it to retain vacuum after disconnection, making it a more advanced alternative suited to demanding use cases.

In summary, the M8 system is ideal for simpler builds focused on temporary vacuum testing or pressure equalization during disassembly, while the M10 version is better suited for vacuum retention and dual-purpose port configurations.

Alternative M10 Vacuum Port Option

Sold Separately

The Subsea M8 Vent & Vacuum Plug offers a compact, modular solution for vacuum testing and passive venting of subsea enclosures. For applications requiring long-term vacuum retention, the larger Subsea M10 Self-Sealing Vent & Vacuum Plug provides enhanced sealing and automation.

M8 Vent & Vacuum Plug
Designed for short-term leak testing or manual pressure equalization, the M8 system allows hose-based vacuum testing but does not self-seal after disconnection. It is ideal for temporary use during enclosure assembly, disassembly, or troubleshooting in shallow to mid-depth deployments.

M10 Self-Sealing Vacuum Plug
Engineered for persistent vacuum retention, the M10 version includes an internal valve and locking cap that automatically seals after vacuum is applied. This makes it better suited for sealed systems during transport, storage, or extended subsea missions.

Key Differences

Vacuum Retention: M8 must remain connected to a hose; M10 self-seals after pump removal.
Use Case: M8 is best for leak testing and temporary access; M10 supports long-term sealed deployments.
Components: M8 includes a threaded copper plug; M10 includes a valve-integrated plug and lock cap.
Mounting Size: M8 uses a smaller M8 threaded port; M10 requires an M10 bulkhead fitting.

Subsea M10 Self-Sealing Vent & Vacuum Plug

Compatible Subsea Enclosure Options

Sold Separately

The Subsea M8 Vent & Vacuum Plug integrates with a wide range of Blu-Sub subsea enclosures using a standard M8 bulkhead port. It should be installed into a properly sized through-hole (Ø8.1 ± 0.1 mm) with adequate panel thickness to ensure proper compression of the O-ring. Always verify the sealing surface is flush and debris-free before conducting vacuum testing.

Subsea Watertight Enclosure Box
Compact aluminum housing rated to 300 m, pre-drilled with twenty M10 ports. To install an M8 plug, custom drilling of an M8 port is required.

Subsea Enclosure Acrylic Tube
Transparent cast acrylic tube rated to 250 m. Compatible with aluminum or acrylic end-caps that can be custom-drilled with an M8 port for use with the vent and vacuum plug.

Subsea Enclosure Aluminum Tube
Rugged housing rated to 1,000 m. Compatible with Blu-Sub aluminum or acrylic end-caps featuring an M8 mounting hole or blank area suitable for drilling to integrate the plug securely.

Compatible Installation Tool

Sold Separately

This product can be installed using the Universal M8/M10 Installation Wrench, a dedicated tool designed for Blu-Sub M8 and M10 bulkhead-style components such as penetrators, switches, sensors, and connector-style hardware.

Its compact dual-end design allows installation in tight or closely spaced layouts, while cable-pass slots allow the wrench to slide over pre-attached cables, enabling installation or servicing without disconnecting wiring.

Universal M8/M10 Installation Wrench

SHIPPING LIST

M8 Enclosure Vent:
1 x Enclosure Vent
1 x O-ring
1 x Nut

Vacuum Plug:
1 x Vacuum Plug

Technical Specifications

Item	M8 Enclosure Vent
Material	Aluminum + Stainless Steel
Appearance	Stainless Steel Natural Color Plug, Black Bulkhead
O-ring Size	Ø10 × 1.5
O-ring Material	FKM75 Brown Fluorine Rubber

Maximum Rated Depth	1,000 m / 3,280 ft
Design Lifetime	3 years or 500 cycles
Temperature Rating (air)	-25 ~ 60 °C / -13 ~ 140 °F
Temperature Rating (water)	-4 ~ 40 °C / 32 ~ 104 °F
Plug Hex Size	3 mm hex wrench
Plug Material	Stainless steel
Bulkhead Material	Aluminum
Bulkhead Thread	M8×1
Filter Size	60 mesh
Filter Material	Stainless steel

Item	Vacuum Plug for M8 Enclosure Vent
Material	Copper
Appearance	Copper – Natural Color
Compatible Hose	Inner Diameter 5 mm / Outer Diameter 8 mm
Self-Sealing	No

Mounting Hole Dimensions

Recommended Size	Enclosure Vent
Recommended Bulkhead Through Hole Size (A)	Ø8.1 ± 0.1
Hatch Cover Thickness (B)	14 mm
Surface Range (C)	17 mm

Does the plug need to be tightened very tightly?
No, overtightening is unnecessary. Simply tighten until flush with the surface. Excessive force can make removal difficult, but it does not improve sealing performance.

Under what circumstances is it needed?
It is recommended for any watertight enclosure to allow air exchange or vacuum testing during assembly, disassembly, or storage.

When removing the plug, will the enclosure vent loosen and come off?
It’s possible. To prevent this, apply threadlocker to the bulkhead and nut. Do not apply threadlocker to the plug itself.

Is it necessary to apply lubricating grease every time the plug is removed?
Yes, applying grease helps check the O-ring condition and ensures smooth installation. It also extends the life of the sealing surface.

3D Model Viewer

Note: The 3D model shown above is for reference purposes only. It may include components, accessories, or alternate sizes not included with the product. For simplicity, only a single representative size is typically displayed when multiple versions exist. Please refer to the product Shipping Guide for detailed information on included contents and size-specific differences.

Download 3D Model (STEP) - M8 Vent & Vacuum Plug