{"product_id":"235-buna-n-backup-ring-90a-durometer-3-131-id-0-118-thick-black-pack-of-25","title":"235 Buna-N Backup Ring, 90A Durometer, 3.131\" ID, 0.118\" Thick, Black (Pack of 25)","description":"\u003ch3\u003eKey features\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eContoured Backup Ring made of Buna-N (Nitrile, NBR) for use with a variety of fluids and hydrocarbons\u003c\/li\u003e\n\u003cli\u003eDurometer (hardness) of 90A\u003c\/li\u003e\n\u003cli\u003eFor use across a wide temperature range from -40 degrees F (-40 degrees C) to 212 degrees F (100 degrees C)\u003c\/li\u003e\n\u003cli\u003eBackup Rings provide added extrusion resistance in high pressure sealing situations\u003c\/li\u003e\n\u003cli\u003e1 or 2 Backup Rings can be used per 1 O-ring, depending on the direction of pressure in the sealing application\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eThis contoured backup ring is made of Buna-N (also called Nitrile or NBR), has a durometer of 90A, and is designed for use in a wide variety of sealing applications.Backup rings provide added extrusion resistance, and prevent damage to O-rings and seals when subjected to high pressures, larger extrusion gaps, and\/or high temperatures. Depending upon the direction of pressure in the sealing application, you can either use 1 backup ring or 2 backup rings. If unsure, it is always best to use two backup rings per 1 O-ring.Buna-nitrile can have high tensile strength, resistance to abrasion, tear, and compression set resistance. It is acceptable for temperature applications between -30 degrees F (-34 degrees C) to 250 degrees F (121 degrees C). It is compatible for use with petroleum, HFA, HFB, and HFC fluids, vegetable oil, alcohol, acids, and aliphatic hydrocarbons. Buna-nitrile is vulnerable to acetone, ethers, esters, ozone, sunlight, and weathering, and should therefore not be used in ozone-generating electric motors, welding equipment, or in applications with exposure to UV light.The durometer hardness of this Buna backup ring is 90A. Durometers measure the hardness of a material a\u003c\/p\u003e\u003cp\u003eFree shipping included. 30-day hassle-free returns.\u003c\/p\u003e","brand":"Belmont Warehouse","offers":[{"title":"Default Title","offer_id":43357840113873,"sku":"BW-B00R4KH01G","price":57.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/3123\/5793\/files\/51LWVXrjQ6L._SL1000.jpg?v=1790986235","url":"https:\/\/belmontwarehouse.com\/products\/235-buna-n-backup-ring-90a-durometer-3-131-id-0-118-thick-black-pack-of-25","provider":"Belmont Warehouse","version":"1.0","type":"link"}