• Plastic vented plugs
  • osmosis Vented plugs


PLASTIC PLUGS are made from a Polyethylene, a thermoplastic polymer consisting of long hydrocarbon chains. The melting point is typically in the range 120 to 180 C (248 to 356 F). The plastic is durable and also recyclable.

The Plastic PLUGS are supplied in 52mm Buttress thread or 52mm BSP thread as well as in 19mm BSP thread and made to international standards These Plugs withstand the SABS drop test criteria. The sealing washers are made from either black BUNA, EPDM or PLASTIC. The product range includes

  • Buttress Threaded Plugs/Osmosis Plugs

  • Buttress Rubber Vented Plugs or Vented Closures

  • Combination Plugs

  • Osmosis Vented Plugs

Plastic osmosis vented plugs

Buttress Threaded Plugs/Osmosis Plugs

The BUTTRESS OSMOSIS VENTING PLUG has a special woven film that is welded onto the inner face of the plug. When industrial/chemical and consumable container products are transported and stored at varying temperatures and altitudes, complications can arise. Containers can expand or collapse due to unequal pressure. These plugs enable the stabilisation of pressure by allowing  the pressure to vent out while not allowing the liquid to pass through and leak. It essentially equalizes container pressure to prevent distortion or damage with vents. 

The osmosis vented plug vents at NO pressure

The osmosis vented plug is used with a variety of products including water and solvent solutions, chemicals, or for use and Surfactants (detergents, wetting agents, emulsifiers, foaming agents, and dispersants)

The osmosis vented plug is fitted with a washer to seal against the profile of the container aperture to prevent leakage. These OSMOSIS venting plugs once in the container can be fitted with a metal pilfer resistant CAPSEAL, but it is advisable to put a small hole in the pilfer seal to release any pressure build up that may occur.

These Plugs are only supplied in Buttress Thread

Buttress Rubber Vented Plugs, pressure venting plugs

Buttress Rubber Vented Plugs/Pressure Venting Closures

BUTTRESS RUBBER VENTED PLUG or pressure venting plug has a moulded rubber vent fitted into a specially shaped hole in the face of the plug. This vent allows the internal pressure build up inside the container to be released. This vent is reversible allowing air into or out of the container as required As mentioned under the Buttress Osmosis a metal pilfer seal can be used as long as there is a small hole to allow pressure to escape or be drawn in.

This Closure vents at approximately 7 bar. Depending on the product being packed there is a choice of the type of washer fitted to the plug; PLASTIC - EPDM, Rubber - Black BUNA Rubber.

These pressure Venting plugs or vented closures are used where internal pressure is to be released from the container after filling or in the case of the rubber vented Plug, to allow pressure into the container and prevents potentially unsafe stacking conditions or change of altitude.

Steel Vented plugs 52mm Plugs are also supplied by Duo Closures

Plastic Products, vented closures

Combinations Plugs

COMBINATION PLUGS made from polypropylene ,are 52mm Buttress threaded with a 19mm (3/4") centre hole fitted with a 19mm (3/4") BSP Plug. The 19mm Plug can be removed to fit a tap if required.

These Plugs are not vented.



PLUG WASHERS are made in PLASTIC, EPDM, or BUNA and come in 19mm or 52mm sizes.

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