Pipe Plugs

What is a Pipe Plug?

A pipe plug, also referred to as a drain plug or a filler plug, is a cylindrical fitting with a drive section at one end and a threaded shaft on the other; it is designed to seal the end of a threaded pipe to dead end the flow of fluid when you no longer need to use the opening. It is an essential device in plumbing and is used in hydraulic systems, pharmaceutical fittings, gas fittings, and many more applications. Huyett carries a variety of pipe plugs in a wide array of sizes, materials, and finishes.

Pipe plugs are used to thread into the ends of pipes and stop the flow of the fluid in the pipe for several reasons. These include maintenance, leak detection, bypassing, and blocking, among others. This mechanism also seals out dirt and debris, so they can be used to prevent contamination during plumbing or construction jobs. Typically, a pipe plug is a temporary addition to an application.

Considerations

Before purchasing pipe plugs, there are a few things to consider about your application to ensure you're choosing a suitable fastener.

Pipe Thread Size: It's important to not only know the inside diameter of the pipe to match with your plug, but also the pipe's thread size. The threads' inch or metric designations should match the plug, and the thread size should be determined by a thread chart.

Drive Tools: You will need to know the type of drive tool you plan to use in your application, as this will determine the pipe plug head style you need.

Fluid Type: What type of fluid normally flows through the pipe? The plug needs to provide a leak-proof seal, which means its material and finish needs to withstand any potential corrosion it could experience from the specific fluid.

Types

Huyett offers several types of pipe plugs to help you choose the right fastener for your application. The style differs based on the head style of the plug; each type will require slightly different installation tools.

Hex Head: Features a flat, solid hex head for installation with a wrench
Hex Socket: Features a countersunk hex head for installation with a hex key or rachet wrench (can sit flush in the pipe)
Square Head: Features a protruding square head for installation with an adjustable wrench or pipe plug square socket
Square Socket: Features a countersunk square head for installation with a square drive pipe plug socket (can sit flush in the pipe)
Slotted: Features a flat, slotted head for installation with a flathead screwdriver (can sit flush in the pipe)
Six Lobe: Features a countersunk star-shaped head for installation with a Torx bit socket

Pipe Plugs and Sockets: The Difference

Simply put, both types of plugs function the same. The main difference between a pipe plug and a pipe plug socket is the head style - the former features a flat or protruding head, while the latter features a countersunk head. The two styles require different installation tools, but beyond this, the only other difference is that sockets can sit flush in the pipe.

Standards

Not all pipe plugs are covered by standards. For the ones that are, the standards regulate either or both the manufacturing and the design of the part. Within the design, standards largely dictate the dimensions and measurements of the part. Here is a list of common pipe plug standards and what they cover:

SAEJ531: An automotive standard that requires specific dimensions and NPTF threads.

ASME B16.11: Covers tolerances, markings, ratings, materials, and dimensions; only applicable to hex and square head types.

ASME B16.14: Offers technical information for certain plugs made from casting, ductile iron and steel.

DIN 906/158: Governs metric tapered hex socket plugs.

DIN 906/3858: Governs British tapered hex socket plugs.