Parco Blog

Parco to Exhibit Rubber Seals at OTC 2012

Parco will join more than 2,000 companies next week exhibiting at this year’s Offshore Technology Conference in Houston, Texas. OTC is held annually at Reliant Park and brings together more than 60,000 attendees from more than 110 countries to focus on the latest technology in drilling, exploration, and production of oil and gas.

If you’re in the Houston area, visit Parco’s staff in Reliant Center at booth 3481.  

Parco has more than 70 years’ experience in compound development for elastomeric seals. That’s why major oil field companies have specified Parco’s O-rings, packing elements, rubber-to-metal bonded parts, compensators, back-up rings, and t-seals for their toughest down-hole jobs. Parco’s seals are made from compounds specially formulated to resist high temperatures, abrasive environments, and harsh chemicals.   Parco significantly expanded its business to the oil field machinery industry earlier this year when it acquired Double E, a leading manufacturer of production tools, custom molded rubber seals, and custom machined parts. Parco is now one of North America's largest suppliers of rubber seals and machined parts to the oil field machinery industry.

Shelf Life of O-Rings and Molded Rubber Seals

When do O-rings and rubber seals go bad?  

O-rings and rubber seals tend to last for many years. The shelf life depends primarily on the material the seal is made from. Below is a chart to help you approximate the shelf life of common materials. You can also use our O-ring Shelf Life Tool to see the shelf life of specific Parco compounds.  

How do I properly store O-rings and rubber seals?  

Make sure you keep the bag the O-rings or rubber seals were originally supplied in. That bag will contain a label with the cure date for the parts. Rubber seals should be kept around room temperature. Extreme heat and cold can shorten the shelf life of the seal. Ideally, rubber seals should be kept in a sealed bag to limit exposure to humidity and dust, and placed somewhere they are protected from light.

Fuel-Dispensing Seals

O-rings and Custom Molded Rubber Seals for Fuel-Dispensing Applications

Parco has provided the fuel-dispensing equipment industry with high quality O-rings, rubber-to-metal bonded parts, and other custom molded seals for decades. Parco’s fuel-dispensing O-rings and custom molded rubber seals are made from compounds that have very low compression set for extended service life.

Parco offers three popular compounds to meet the needs of many sealing applications in the fuel-dispensing equipment industry. Parco’s 2295-70 compound is a 70-durometer black nitrile. It is fuel-resistant, alcohol resistant, and UL-listed. Our 9131-75 compound is also fuel resistant and UL 157 listed. It is a 75-durometer, peroxide-cured, black fluorocarbon. Some fuel dispensing seals are used in very cold environments. If you intend to purchase seals that need to withstand service temperatures as low as -40°F, consider Parco’s compound 9167-60. Seals made from that compound are UL-25 listed and resist fuels in a wide range of temperatures.

If you require a compound other than what is described above, you can search our extensive compound library using our Compound Wizard. That tool allows you to select the desired elastomer, durometer and key properties required for your sealing application.  If you still don’t find what you need, we invite you to direct any compound questions to our R & D department at lab@parcoinc.com.

Remember, to maintain a pumping apparatus, fuel-dispensing O-rings and custom seals should be inspected for normal wear when other equipment is being serviced or examined. Should a seal experience excessive wear or distortion, it should be replaced so other problems don’t arise.

Elastomer Selection for O-rings and Rubber Seals

What elastomers are seals made from?

The most popular elastomers used to make O-rings and rubber seals are nitrile (buna), fluorocarbon, ethylene-propylene, silicone, neoprene, polyacrylate, fluorosilicone, hydrogenated nitrile, aflas, and butyl. When you have no idea where to start, it’s usually a good idea to consider nitrile first. It can meet more than fifty percent of all sealing needs.

What should I consider when choosing an elastomer for my O-rings and rubber seals?

There are five key factors you should consider when specifying an elastomer for your seals. We’ll go through each one briefly.

1. Temperature Capabilities
What temperatures will the seal be exposed to? Service temperatures can vary widely among different elastomers. Some are better suited for low temperatures and others for high temperatures. If you specify the wrong elastomer for low temperatures, the seal can become brittle and crack. High temperatures can accelerate the life of the seal if the wrong elastomer is used.

2. Fluid Compatibility
Most seals need to block fluid and prevent leaks. Elastomers can withstand a variety of fluids but some are better at resisting certain types of fluids. A seal made from an elastomer not suited for a particular fluid can swell or deteriorate. You can use our Chemical Resistance tool to search more than 900 fluids to find a Parco compound and elastomer that best fits your needs.

3. Abrasion and Tear Resistance
If seals are used in a dynamic application, they should be made from an abrasion-resistant elastomer. Otherwise, the seal can be nicked, cut, or torn during operation or installation. You may want to consider hydrogenated nitrile, aflas, or butyl elastomers.

4. Differential Pressure Resistance
A seal should function properly when equal amounts of pressure are applied on both sides of the seal. When you have high differential pressures, the seal will most likely fail by extruding from its groove. Typically, extrusion can be avoided by using a harder material or using back up rings.

5. Price
Some elastomers are inherently more expensive than others. Nitrile is typically the cheapest material. Fluorocarbon and fluorosilicone elastomers are on the higher end of cost.

For more detailed information on elastomer selection, download our Elastomer Selection Guide.

Prototype O-rings, Back-up Rings, and Custom Shapes

How quickly can I get prototype O-rings and custom rubber seals?

If you need prototype seals fast, consider Parco’s Rapid Prototype Program. Parco knows time is critical during product development and design improvement. If you need prototype O-rings or custom shapes, rely on Parco to provide them in as few as three working days. Parco offers three options for prototype seals to get you the seals you need, when you need them.

1. Standard O-rings and Back-up Rings (3 business days)
2. Non-Standard O-rings or Simple Custom Shapes (5 business days)
3. Complex Custom Shapes or Ground Parts (5 business days)
    

To learn more, download a copy of Parco’s Rapid Prototype Program brochure or contact a customer service representative at 909-947-2200.

NSF 61 O-rings & Custom Molded Rubber Seals

Parco offers a variety of rubber seals for the water filtration industry, including U-cup seals and concentration seals.

Parco has more than 15 years of experience providing seals that meet NSF/ANSI Standard 61 to the water filtration industry. Parco has stringently adhered to NSF 61 guidelines, producing water filtration O-rings and custom molded rubber seals that prevent leaching of chemicals or contaminants.  Our seals offer outstanding resistance to swelling caused by chloramine-treated drinking water. They’re also available in FDA conforming and internally-lubricated compounds.   

If you need stocked general-purpose O-rings that meet NSF 61, consider Parco’s 5323-70 compound. It’s a low cost, peroxide-cured EPDM that’s also FDA conforming. You can check stock online and order today. If you are selling parts in the UK and need O-rings to meet WRAS, contact Parco at 909-947-2200 as ask about our 5325-70 compound.

For a listing of Parco’s full line of NSF 61 compounds used in O-rings and custom molded rubber seals, download a copy of our NSF 61 Listed Compounds brochure.

Viton® Extreme (ETP) O-rings & Rubber Seals

Certain elastomers can make O-rings & rubber seals expensive.

When someone looks at an O-ring or molded rubber seal, they usually don’t think it can cost upwards to several hundred dollars apiece. Most of the time, general-purpose seals are only a few cents or dollars apiece. The cost of the O-ring or rubber seal is greatly affected by the elastomer used to make it. The most popular and least expensive elastomer is nitrile (Buna). More than fifty percent of sealing needs can be met using nitrile. While every seal serves the same purpose (to block the passage of liquid or gas) they are all exposed to different environments. Many demanding industries like oil field machinery and chemical processing can expose rubber seals to extreme temperatures and caustic fluids on a daily basis. Sometimes, rubber seals made from specialty elastomers are the only thing that will withstand those applications. You certainly wouldn’t want to use the same O-ring you put in your kitchen sink as you would four miles below the earth’s surface in a drill bit.

Rubber seals made from perfluoroelastomers offer the best resistance to high temperatures and chemicals…but at a high cost.

Rubber seals made from perfluoroelastomers can resist continuous service temperatures of up to 600°F. There is no other elastomeric material that can offer such resistance. Standard elastomers can usually seal up to 400°F. Pefluoroelastomers also have inherent reisistance to aggressive chemicals. O-rings and molded rubber seals made from perfluoroelastomers resist more chemicals than seals made from any other elastomer. As you may have guessed, any seal made from a perfluoroelastomer will cost a significant amount. Unless you’re willing to shell out the big bucks, you might want to consider a viable alternative.

Parco’s 9166-75 Viton® Extreme (ETP) offers a less expensive alternative to perfluoroelastomers.

Parco’s compound, 9166-75, is made from a Viton® Extreme (ETP) polymer. While that material can only be used in service temperatures up to 400°F, it offers reliable service similar to a perfluorelastomer in aggressive chemicals, but at a fraction of the cost. O-rings and molded rubber seals made from perfluoroelastomer can cost up to six times more than those made from Viton® ETP. For more information on Parco’s Viton® ETP seals and chemical compatibility, download our 9166-75 Fluorocarbon Seals brochure. You can also request a quote online and see the savings for yourself.

Parco O-rings Go Mobile

O-ring & Rubber Seal Inventory App for Your Smartphone

 Parco has made it easy for customers to check stock for general purpose O-rings and custom molded rubber seals from anywhere in the world. All you need is a smartphone and our Inventory Inquiry application. You can download the application for free from Apple’s App Store and Android’s Marketplace. The app can be used on your iPhone, iPad, iPod, and Android touch devices.

Check General-Purpose O-ring Inventory

If you aren’t a current customer, then you’re probably unfamiliar with Parco’s part and compound numbers. Not to worry. You can still check our finished goods inventory for stocked general-purpose O-rings. Just enter the AS-568 O-ring size in the Parco part field and use any of the following popular compound numbers for the material you’re looking for: 

Compound   Description

120070        Silicone O-rings, 70-durometer, red

Military & Aerospace O-rings

Make Parco Your First Choice for Military & Aerospace O-rings

Parco manufactures diverse rubber products used across multiple industries. Some of the most exacting requirements we are proud to meet are the specifications established by the aerospace and defense industries. We currently offer O-rings to meet 28 military and aerospace specifications.

Parco opened in 1941 as the first company in the United States to manufacture O-rings. We quickly developed a reliable reputation for supplying high quality military and aerospace O-rings by establishing a cutting edge R & D department. We have continued to grow in stature and capacity over our 70 years in business. Given our history and commitment, we maintain our position among an elite number of suppliers that are short-listed and qualified to supply QPL rubber seals. Qualified Products Lists (QPL) standardize specifications and supplies for the Defense Department.

For additional information on our military and aerospace seals, download our Military & Aerospace O-rings brochure. That brochure includes a full list of Parco’s compounds for military and aerospace specifications. 

Viton O-rings vs. Fluorocarbon O-rings

What is the difference between Viton O-rings and fluorocarbon O-rings?

We are often asked what the difference is between Viton O-rings and fluorocarbon O-rings. An easy way to understand the difference is to compare them to an iPad and a tablet.  In many ways, an iPad and a tablet from a manufacturer other than Apple will perform many of the same functions. However, what name do you hear most often when people talk about tablets and which tablet is your child, spouse, or friend asking for as a gift?  Most likely, you answered, “An iPad.” Why? The main reason is the iPad is a brand name that’s recognized so well among consumers. Apple has done a great job innovating and advertising their product. In much the same way, we can view Viton as the iPad and fluorocarbon as the other tablets. iPad is a registered trademark of Apple and Viton is a registered trademark of Dupont Performance Elastomers. Like Apple, Dupont has offered significant advances over the years in its products and has extensively advertised its various brands. 

Are Viton O-rings better than fluorocarbon O-rings?

So now that you have a better understanding of the difference between Viton and fluorocarbon, you might be asking yourself which is better. Should you buy Viton O-rings or fluorocarbon O-rings? Well, that brings us back to the iPad versus tablet example. Not all consumers have the same needs. Most consumers will likely consider various tablet features such as price, durability, apps, and operating systems before making a purchase. Someone deciding whether to buy Viton or fluorocarbon O-rings should also look at all the options before specifying a particular material.  Things to consider include a seal’s temperature capabilities, fluid compatibility, abrasion and tear resistance, differential pressure resistance, and price. 

For help deciding which fluorocarbon is right for your application, download a copy of Parco’s Fluorocarbon Selection Guide.  That guide includes the characteristics of fluorocarbon types and an overview of Parco’s popular fluorocarbon compounds.