Mechanical Pipe Plugs

Mechanical Pipe Test Plugs are primarily used in applications where safety is paramount. Mechanical plugs are different from inflatable in that the seals are solid and cannot lose inflation pressure.

Sealfast® Mechanical Pipe Plugs feature the same lightweight aluminum construction as the LP and MP series of Inflatable Pipe Plugs. These mechanical pipe plugs are mechanically actuated by tightening a series of rim nuts around the periphery of the pipe plug. This squeezes the rubber seal into the I.D. of the pipe. 

High Quality Mechanical Pipe Plugs

At Mechanical Research & Design, we strive to offer only the best mechanical pipe plugs available today. Along with superior mechanical pipe plugs, we offer inflatable door seals, pipe pullers, we even offer custom seals.

Our mechanical pipe plugs offer the following features:

  • Long duration/long term installations
  • Installations where seal inflation air is not available
  • Sizes 1/2″ to 144″

Standard Mechanical Plug Series

Standard Tools Restrain and Seal on Pipe I.D. / for Carbon Steel Pipe S40 or thicker
Low pressure – LPM® Series  <25 PSIG Sizes .5″ I.D. thru 144″ I.D.
Medium pressure – MPM® Series <100 PSIG Sizes .5″ I.D. thru 144″ I.D.
High pressure – HPM® Series 100 PSIG to > 5000 PSIG Sizes .5″ I.D. thru 144″ I.D.

Note: Plugs are customized from the standard for different pipe materials & thinner pipe thickness.

How a Mechanical Pipe Plug Works

  • Tighten restraint screws to center the plug and provide full pressure restraint in the pipe
  • Tighten mechanical seal actuation nuts to provide leak-tight seal
  • Fill test region through the test port and bleed air through the vent port
  • Close the vent and bring the system up to test pressure

*Note: In normal pressure conditions, pressure will drive sealing backplate into the mechanical seal to “self-seal” the pipe.

Contact Us today for standard design literature, product specifications and sizes larger than 144″ for custom design submittals.

Typical Materials of Construction
  • Lightweight structural aluminum plate
  • Stainless and bronze fasteners
  • Can be fabricated from nearly any material, depending upon environmental concerns:
    • Stainless steel (304, 316, Nitronic, 17-4 PH)
    • PVC and other plastics
    • Carbon steel
    • Titanium
    • UHMW
    • Delrin
    • PTFE
    • Cobalt 6B
Typical Sealing Surfaces
  • Carbon steel and stainless steel pipe
  • PVC, HDPE, PVC-line pipe, Polyethylene, Polypropylene
  • Composites, FRP, Graphite
  • Concrete pipe, RCP, etc.
  • Ductile iron
  • Copper and stainless tubing
  • Hoses
Coatings and Anodic Protection
  • Hard-coat anodized coatings
  • Epoxy coatings
  • Flame spray coatings
  • Zinc and magnesium anodes
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