You have a lot of options when you’re looking for gasket material, and some of them can get very expensive. While it may be tempting to select a highly engineered polymer with exceptional temperature and chemical resistance properties, ask whether that’s what you really need. In many cases, you may be better off using Styrene Butadiene Rubber, better known as SBR Gasket Material.
SBR Gasket Material: An Alternative to Natural Rubber Gasket Material
SBR red rubber gasket material was developed during WWII. At the time most rubber came from Asia, and as more rubber was needed for tires, scientists were searching for an alternative. Styrene-Butadiene Rubber, derived from the Buna polymer developed in Germany in 1929, met that need.
Natural rubber has many things in its favor as a material for gaskets as well as tires. It’s soft and elastic, with good compression recovery. That lets it conform to uneven flange faces and expand to fill the gaps. However, it doesn’t fair well outdoors and its temperature range and chemical resistance are so-so at best. SBR improves on natural rubber with a wider temperature range and better weathering and chemical resistance properties. It’s also a very economical choice.
Don’t Over-Engineer the Application
SBR Gasket Material isn’t the highest performing gasket material available, but for many applications, it’s good enough. Use it when temperatures won’t go above 170° F or below -30° F and for sealing against air, water and steam. Use it when flange faces may be uneven, and use it in applications that need good impact strength and abrasion resistance.
Don’t use SBR gasket material to seal against hydraulic fluid, solvents or oils as this will make it swell excessively. Neither is it a good choice for outdoor applications with exposure to UV and/or ozone.
Many alternative gasket materials provide higher performance but at a higher price. Rather than considering what might happen in-service, focus on what’s known for sure. You may find that SBR is up to the task and will save you some money. For more information, discuss your application with the specialists at Hennig Gasket & Seals.