Large O-Rings: Types, Advantages & Disadvantages

large o-rings

Different Needs Call for Different Large O-Ring Specs

Large o-rings (also called giant o-rings) are needed in multiple applications where large, heavy machinery and equipment are in use. There are a variety of different production methods to make large o-rings, but understanding which one makes the most sense for you and your business ultimately comes down to different application criteria. Before settling on a production method, you should already know several specifics about the job you want these seals to accomplish.

First, consider the size you’ll need. Large o-rings are typically defined as those that have a diameter of 35” or larger. If you’re seeking a smaller size, then not all of these production methods will be your best option.

Another factor is lead time. For larger and more complicated (number of joints needed) o-rings, you’ll need to allow more time from the manufacturer before you can expect to have them in hand for use.

Next, you need to consider the cost and the application itself to which the large o-rings will be applied. Not every production method will produce o-rings suitable for dynamic, oil and gas, or vacuum applications. Similarly, if your budget is limited — or if you’re prototyping a seal for a new application — a more cost-effective production method may be preferred.

Production Methods for Large O-Rings

The choice in the production method used for your large o-ring needs will hinge on the answers to the questions above. Each of the three primary production methods will have its own strengths and weaknesses, but all will offer potential benefits and an ideal fit for your project depending on what application the seals are designed for and in what stage of development your project might be in.

Continuous Molding is simply the best option for the production of large o-rings needed for high performance in dynamic, oil and gas, high-pressure, and vacuum applications. This proprietary molding method will produce nearly the same quality as traditional fully molded techniques with almost undetectable joints, which will increase the consistency of higher-performance sealing. Due to the exacting details of the production, a longer lead time — from two to four weeks — is needed. The scrap rate associated with adhering to those details, and the inclusion of any specialty materials in production, can make this a more expensive method as well.

Continuous Molding works by molding and curing an extruded cord into an arc that then gets fed back through the system. The process creates a continuous ring with uniform properties throughout the ring — no cuts, no parting lines, no flash.

This process produces an almost undetectable joint — both visibly and mechanically — when compared to the traditional spliced and vulcanized process. This is particularly useful in ultra-high temperature and harsh chemical environments because it enables the use of our Markez® perfluoroelastomer (FFKM) materials, which cannot be spliced and vulcanized and still maintain their chemical resistance.

In addition, each machine can produce a single cross section in any size diameter when utilizing the continuous molding process. That eliminates the need for custom tooling on large rings.

Precision Vulcanization, also referred to as the Precision Spliced and Vulcanized method, will offer the best value for prototyping and basic applications. This method yields consistent quality, and the angled joint — fully cured extruded cord is typically cut to length with a 45-degree angle scarf cut end — increases the bond surface area and strength which will allow for better sealing with less leak potential. This method will have a higher cost than standard vulcanization but a similar lead time (three to 14 days) and is not recommended for vacuum, high-pressure, or dynamic applications.

Standard Vulcanization, or the Standard Spliced and Vulcanization method, is similar to Precision Vulcanization with the differences being that sometimes only a 90-degree angle cut can be used (depending on material and thickness) and the joint quality can vary as they are usually produced by hand. The rubber-based adhesive used does offer a flexible, compressible joint, but large o-rings produced with this method should only be used for basic static, low-pressure, and short-term applications. Lead times run from three to 14 days.

Marco Rubber Can Help You Sift Through the Options

Finding the right large o-ring for your application can be a tricky process. You’ll need the exact specifications for the applications — how big does the o-ring need to be, when do you need it, and what’s the budget — and then meld that knowledge with the best production method needed to achieve the desired results.

You’ll also need to decide on the material to use for your customized large o-ring. The choices here are many, and each will provide certain benefits under specific circumstances. Even with the right specifics and the preferred production method, if your company fails to account for the material aspect, then it could lead to a substandard performance for your application.

For instance, if your application calls for o-rings that need to stand up to high temperatures and high pressure situations, while also providing substantial chemical resistance, you’ll need a material designed specifically to support those performance parameters. Markez® high performance perfluoroelastomer (FFKM) is a leading material option to consider here.

Introduced exclusively to Marco Rubber customers more than 15 years ago, Markez o-rings today are offered in wide release. With a temperature resistance of up to 625ºF (329ºC) and produced from nearly identical ingredients as other high-priced brands, Markez o-rings will deliver a more affordable alternative in various industries such as petrochemicals, paint, and ink applications where resistance to harsh solvents is also needed.

Pairing the right material with the correct specs and the proper production method is what separates Marco Rubber & Plastics from others in the same space. With more than 40 years of experience, we’ve developed a huge inventory network of quality products and generate additional value for our customers with responsive service and expert engineering support.

Our development of market-leading online reference tools and documentation means you’ll have all the information you need to make informed decisions to outfit your applications for the best results. And our online store provides an easy one-stop shop for ordering a variety of o-rings and other sealing products — many of which ship same-day.

We’ve helped seal the success of more than 14,000 repeat customers worldwide and look forward to offering quick, customized solutions for your large o-ring needs.

Seal Your Success with Large O-Rings from Marco Rubber & Plastics

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