Pipe end plugs and sealing discs: robust tools for confined workspaces

Conventional pipe stoppers and test plugs are not suitable for every application. In some cases, there simply isn't enough space in the pipe or the back pressure is too high, causing the plug to slip out. Temperature can also play a role: if the pipe is too hot, even the robust rubber material can melt. If the plug needs to withstand exposure to chemicals (such as alkalis or acids), standard pipe stoppers often won’t be sufficient.

The pipe end plugs and sealing discs from MOWOTAS provide a crucial alternative for these demanding situations. Thanks to their design and technical features, they are suitable for a wide range of applications. Like conventional plugs, they can also be used for sealing and tightness testing.

Especially in confined spaces, sealing discs are beneficial due to their short length. Their mechanical tensioning design makes them a simple tool that can be operated without the need for a compressor. They can be used across various diameters and pressure ranges, making them the right tool for nearly every job.

Common Applications for Our Pipe End Plugs & Sealing Discs:

• Sealing of aquariums and ponds (also available without copper parts)
• Sealing of gas pipes in the industry
• Foundation for casing, e.g. as a centering device
• Closing of dead-end pipes
• Testing of heating pipes
• Sealing of pipes in power plants and heating systems (Silicone variant up to 230°C)
• Sealing of short pipes or where space is limited
• Tightness testing in confined spaces

Features of Our Pipe End Plugs & Sealing Discs

Mechanical Pipe Plugs
Our pipe end plugs for diameters ranging from DN 12 to DN 90 (plug length 20 – 40 mm) are compact components designed and tested for internal pipe pressures up to 8 bar. These plugs are made from water- and oil-resistant nitrile rubber and metal parts made of galvanized steel. By tightening the wing nut, pressure is applied to the rubber component, effectively sealing the pipe. For internal pressures exceeding 1 bar, the pipe end plugs must be secured to prevent slipping. These are available with or without a through-hole.

High Pressure Pipe Stoppers
These plugs operate on the same principle as the standard pipe end plugs, but the high-pressure variants are designed for diameters ranging from DN 85 to DN 255. By tightening a nut on a threaded rod, a seal is achieved that can withstand internal pressures up to 12 bar. For internal pressures exceeding 1 bar, these pipe end plugs must also be secured to prevent slipping. Available with or without a through-hole.

Pneumatic Pipe Plugs
Our pneumatic pipe end plugs, designed for diameters from DN 200 to DN 600, are ideal for sealing or tightness testing on larger pipelines. They consist of a robust metal core with a through-hole and are covered with high-quality rubber. The rubber coating can be inflated via a simple tyre valve and withstands up to 4 bar of back pressure. Temperature range: -20°C to +80°C.

Sealing Discs
Our mechanical sealing discs, designed for diameters from DN 40 to DN 600, are ideal for space-saving sealing and testing of pipes. They are suitable for all types of pipes and are resistant to both wastewater and drinking water.
The maximum back pressure varies depending on the diameter, ranging from 2.0 to 0.3 bar. These discs are available in aluminium or steel versions, with one or two seals made of NR rubber and through-hole options.

How Can We Assist You? Get in touch, and we will be happy to answer any questions you have!

Author: Elisabeth Pietraß | You can find out more about the author of this article by visiting her LinkedIn profile.