O-Rings & Pipe Plugs at G.L. Huyett

What is an O‑ring?

O‑Rings are an "O" shaped, or torus, ring made from a flexible polymer material such as neoprene or silicone used to seal connections requiring the transmission of fluids or gasses. These rings are often available with disc or "x" cross‑sections and are designed to fit into the groove of a fitting. When two parts of a fitting are joined, the O‑ring is compressed to create a tight, leak proof seal. While simple in design, O‑rings are a critical component in a variety of pressure systems found in industrial, agricultural, and automotive applications.

How do O‑rings work?

The functionality of an O‑ring is simple, however, its importance is critical. O‑rings are placed in the interior, exterior, or face grooves of a fitting assembly. When the fitting assembly is joined, the O‑ring is compressed creating secure contact between the two mating components of the fitting assembly. As fluid or gas is introduced into the system, the medium works its way into the unsealed void between the fitting parts. When the fluid or gas medium reaches the O‑ring, the O‑ring is pressed against the surface of the two fitting components, thus preventing the fluid or gas medium from escaping.

O‑Ring Material Types

O‑rings can be manufactured from a variety of elastomer combinations, each possessing different qualities to make them ideal for a variety of applications. We’ve broken out the different materials below to help you choose the right o-ring for your needs.

• AFLAS® — is a proprietary copolymer with tetrafluorethylene (TFE) and propylene made by Asahi Glass Co., Ltd. It possesses excellent heat and chemical resistance. It also possesses high electrical resistivity. Typical Shore A hardness of 70‑90.
• Buna‑N — Also called Nitrile or NBR, is a common rubber material known for its excellent resistance to a variety of mediums including alcohols, fuels, silicone greases, hydraulic fluids, and petroleum based oils. It also possesses good tear resistance and rebound. Some of the drawback of Buna‑N however is that it is susceptible to environmental elements such as UV light and extreme heat. Typical Shore A hardness of 70.
• Ethylene Propylene (EPR) — Ethylene propylene based O‑rings provide excellent chemical and thermal resistance. This family of O‑rings includes EPR and EPDM polymers, both of which provide very similar performance and are often referred to interchangeably. Ethylene propylene polymers work well with a variety of mediums including alcohols, brake fluids, and silicone oils. They are often used in automotive cooling systems and typically possess a Shore A hardness of 70.
• Neoprene — Neoprene, also known as chloroprene (CR), is a general purpose material known for its resistance to weather and petroleum based fluids. This cost effective material also possesses excellent corrosion resistance against ammonia and Freon, making it suitable to be used in refrigeration and air conditioning units.
• Silicone — Silicone is a highly versatile elastomer able to withstand a wide range of temperatures, fungal growth, UV radiation, and weathering. Silicone is very similar to EPDM polymers, however, silicone possesses a far greater resistance to heat. Silicone o‑rings are commonly used in petroleum and water applications. Due to its low abrasion resistance, it is best suited for static applications.
• Viton™ — Viton, or FKM, is a fluorinated elastomer that possesses high temperature resistance while maintaining good mechanical properties as well as providing oil and chemical resistance. FKM is used in many applications including automotive, chemical, hydraulic, and appliances.

How to measure O‑rings?

O‑rings are measured by size and hardness. Hardness is measured using a durometer gauge which indents the elastomer and provides a reading. The larger the indentation, the lower the number, indicating a softer material. The smaller the indentation, the higher the number, indicating a harder material. The amount of deformation in the material relates to a number on a Duro or Shore scale ranging from 0‑100. For example, Shore 20A hardness would equate to something resembling a rubber band whereas Shore 80A hardness would be closer to the composition of a hard hat. The infographic below shows how various O‑rings offered by G.L. Huyett measure on the Shore A hardness scale.

The size of the O‑ring is determined by measuring the outside and inside diameter, as well as the ring cross‑section. Measurements can be made in both imperial and metric depending on the application requirements.

Where to buy O‑rings?

O‑rings can be purchased by phone or online! G.L. Huyett is the proud distributor of a wide range of O‑rings manufactured from a variety of materials to fit nearly any application. If you don't see what you are looking for, give us a call to speak with our knowledgeable and friendly sales team!

What is a pipe plug?

Pipe plugs, sometimes referred to as drain plugs or filler plugs, are a metal, threaded stopper fitted at the end of a pipe or wall of a housing to prevent loss of fluid when an opening is not in use. Pipe plugs are available with NPTF or PTF‑SAE dry seal thread profiles. The PTF‑SAE profile features 1 less thread than NPTF, giving the associated plug a slightly shorter overall length. Pipe plugs are found in nearly every industry where fluid transmission or containment is required including industrial, chemical, agricultural, and automotive.

Pipe Plug Types

There are many different pipe plug configurations to choose from when selecting a pipe plug for your application. They include protruding or socket head designs, tapered threads, and body length. Below are some highlights of common plug head types.

• Square Head – Square head pipe plugs feature a square head that protrudes above the surface of the mating assembly. These can be tightened and loosened using a crescent wrench or a pipe plug square socket. Square head pipe plugs can commonly be found on hydraulic fluid reservoirs.
• Hex Head – Hex head pipe plugs have a protruding hex head whose diameter is wider than the plug's threads. Hex head pipe plugs can be tightened and loosened using a standard socket as well as an open‑end or box end wrench.
• Hex Head Small – Pipe plugs featuring small hex heads feature a protruding hex head whose diameter is narrower than the threads of the plug. Plugs with these heads can also be loosened or tightened using standard sockets or wrenches.
• Square Socket – Square socket pipe plugs feature a square recess in the top of the plug allowing for near flush installation. These pipe plugs can be installed and uninstalled using a square drive pipe plug socket. These are ideal for applications with limited clearance.
• Hex Socket – Hex socket pipe plugs are designed with a hex recess in the top of the plug to provide a near flush installation. These pipe plugs can be tightened and loosened using a hex bit socket. Hex socket pipe plugs work well for areas with limited clearance.
• Slotted – Slotted pipe plugs feature a slot across the top of the plug for use with a standard screwdriver. The head of the socket is flat allowing for near flush installation, making it ideal for applications with limited clearance.
• Six Lobe – Six lobe pipe plugs are designed with a six lobe recess at the top of the plug. The recessed design allows the plug to be nearly flush when installed. These plugs can be installed and uninstalled using a Torx bit socket. The socket design makes this plug ideal for applications with low clearance tolerances.
• Gas Hex Socket – Gas hex socket pipe plugs are designed with a hex recess and feature a shorter thread length than the standard hex socket plug.
• 7/8 Taper Flush – 7/8" taper threads are unique in that they will allow the plug to install flush with the surrounding surface. These plugs can only be installed into tapered NPT or NPTF threaded holes.
• 3/4 Taper Flush – 3/4" taper is the standard taper for NPT pipe threads. Plugs with these threads are not designed to install flush to the surrounding surface.

How to fix a stripped oil drain plug?

Sometimes threads of drain plugs, also referred to as fill plugs or pipe plugs, or their mating parts can become stripped out from excessive use or accidental cross‑threading.

When working with a stripped drain plug, begin by removing it from the mating component and inspecting the plug's threads. If the threads are beyond repair, replace the plug with a new one. If the threads are only partially damaged, they can be corrected using a die with the same thread dimensions as the plug. Simply thread the plug into the die while applying a lubricating oil to the threads of the plug. Thread the plug completely into the die and back to correct the damaged threads.

Next, inspect the threads of the mating component. If the damage to the threads is minimal, a tap of the appropriate size can be threaded into the mating component to correct the damaged threads. If the threads are damaged beyond repair, the mating component may need to be repaired by installing a helical thread insert. When performing the procedure, metal shavings will likely enter the pipe or container being serviced. Make sure to clean out all shavings prior to putting equipment back in service.

Make sure to refer to your engineers' specifications when repairing critical components as some repair methods may not be suitable for all applications.

Where to buy a pipe plug?

Pipe plugs can be purchased from G.L. Huyett either by phone or online! We carry a wide variety of pipe plugs in an array of finishes including black oxide, passivated, clear zinc, and yellow zinc. Hex, square, Torx, and slotted plug types are also available with protruding or socket designs to meet a variety of application requirements. If you don't see what you are looking for or have a custom application, call us to speak with our knowledgeable and friendly Sales Team!