Here you can see the opening and buttress plug on our 30 gallon tight head plastic drum. Notice the coarse large threads on the drum and plug. This is known as a buttress plug. The other variety (this plastic drum has both) is a fine thread plug known as an NPS plug. NPS stands for National Pipe Standard and is the smaller of the two. Each plastic drum comes with one buttress opening and plug and one NPS opening and plug. Both have 3/4″ center reducers which can accept a variety of spigots, faucets, pumps or vent plugs.
|30 Gallon Blue Plastic Closed Top Round High Density Polyethylene
UN Rating: 1H1/Y1.8/100 & 1H1/Y1.4/100 When Vented
Our 30 gallon blue tight head drum has a cover that does not come off. It is made from high density polyethylene and is food grade. This drum has one 2" NPS plug and one 2" Buttress plug.