NPT Port Blanking Plugs

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£3.30

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NPT Port Blanking Plugs – Tapered Thread Port Closures

Seal unused NPT threaded ports with our aluminium NPT Port Blanking Plugs. Designed for compatible female NPT connections, these reusable plugs seal on the tapered thread and provide a simple way to close redundant ports in oil, fuel, coolant and other fluid-system components.

Why Choose Our NPT Port Blanking Plugs?

Tapered NPT Thread

The male NPT thread progressively tightens into the mating female port, with the tapered thread forming the sealing interface when installed using a suitable thread sealant.
Internal & External Hex Options

Choose between a low-profile internal hex design or an external hex head depending on installation space and tool access.
Compact Port Closure

Provides a removable solution for closing unused sensor, gauge or auxiliary fluid ports without requiring additional adapters.
6061-T6 Aluminium Construction

Precision-machined from lightweight 6061-T6 aluminium and finished with black anodising for protection against wear and corrosion.
Reusable Design

The plug can be removed and reused provided the threads and drive surfaces remain in good condition.

What is an NPT Port Blanking Plug?

An NPT port blanking plug screws into an unused female NPT connection to close the port. Unlike Metric and ORB plugs that use a separate O-ring seal, NPT uses a tapered pipe thread that tightens progressively as the plug is installed.

Internal Hex or External Hex?

Both styles use the same NPT connection and sealing principle. The internal hex version provides a lower-profile installed appearance, while the external hex version can be tightened using a conventional spanner or socket. Choose the style that best suits the available installation space and tool access.

Plug Type: NPT Port Blanking Plug For closing compatible unused female NPT ports
Available Styles: Internal Hex / External Hex Choose the drive style to suit installation space and tool access
Material: 6061-T6 Aluminium Lightweight, high-strength alloy
Finish: Black Anodised Protects against wear and corrosion

Connection: Male NPT For installation into a compatible female NPT port
Thread Type: Tapered NPT Thread tightens progressively into the mating female port
Sealing Method: Tapered Thread Seal Use a suitable thread sealant or PTFE tape
O-Ring: Not Required NPT seals on the tapered thread rather than an O-ring
Reusable: Yes Reuse only if the plug, threads and drive surfaces are free from damage

Use a suitable thread sealant or PTFE tape on the NPT thread. Keep sealing material clear of the first thread and fluid passage.

Available NPT port blanking plug options
Product Code	NPT Thread	Drive Style
PLG-PRT-NPT-AL-18NPT-IH	1/8"-27 NPT	Internal Hex
PLG-PRT-NPT-AL-18NPT-EH	1/8"-27 NPT	External Hex

NPT is a tapered thread and must be matched to a compatible NPT port. Do not substitute BSPP or other parallel threads based on nominal size alone.

Sensor Ports
Gauge Ports
Oil Systems
Fuel Systems
Coolant Systems
Unused NPT Ports

Free repair or replacement for two years from the date of purchase. Learn more

Frequently Asked Questions

What are NPT port blanking plugs used for?
They are used to close unused female NPT threaded ports in compatible fluid-system components such as manifolds, sensor blocks, adapters, filter housings and cooler components.
What NPT size is available?
These plugs are available in 1/8"-27 NPT.
How does an NPT port blanking plug seal?
NPT uses a tapered thread. The male plug tightens progressively into the female NPT port and seals on the thread taper when installed using a suitable thread sealant.
Do I need thread sealant or PTFE tape?
Yes. Use a suitable thread sealant or PTFE tape on the NPT connection. Keep excess sealing material clear of the first thread and fluid passage.
What is the difference between the internal and external hex versions?
Both versions use the same NPT thread and sealing method. The internal hex version is installed with a hex key and provides a lower-profile design, while the external hex version is tightened using a suitable spanner or socket.
Is NPT the same as BSPP?
No. NPT uses a tapered pipe thread, while BSPP uses a parallel thread and a separate sealing arrangement. The two connection types should not be treated as interchangeable.
Do NPT plugs use an O-ring?
No. These NPT port blanking plugs seal on the tapered thread rather than using an O-ring.
Are NPT port blanking plugs reusable?
Yes, provided the plug and threads remain free from damage. Remove the old thread sealant and apply fresh suitable sealant before reinstalling.