Nitrile O-Rings | Oil & Fuel Resistant 70-90 Shore A for Hydraulic and Fuel Systems

Product Overview

High-Performance Nitrile (NBR) O-Rings | 70-90 Shore A | Oil & Fuel Resistant

These black NBR (Buna-N) O-rings are offered in 70-90 Shore A options for hydraulic oil and fuel-system sealing enquiries. Identify the oil grade or fuel blend, including ethanol or biodiesel content and additives, together with the operating temperature. Confirm the selected compound for the actual fluid; an NBR designation does not establish compatibility with every fuel.

The Advantages of Nitrile (NBR/Buna-N) Material

Nitrile Butadiene Rubber is commonly called NBR or Buna-N. These names identify the polymer family; hardness, mechanical properties and fluid compatibility depend on the particular formulation. Review the following selection points for the intended service:

• Oil-Service Selection: NBR is an option for selected petroleum oil applications. Identify the oil grade, fuel blend and additives for compound compatibility review.

• Mechanical Properties: Agree tensile, elongation or wear requirements and the test method where these are needed for the application.

• Compression Set: Temperature, squeeze and exposure time affect recovery and sealing performance. Specify any required compression-set test criteria.

• Hardness Options: Select hardness together with groove clearance, movement and pressure. Hardness alone does not establish a pressure rating.

Applications

Hydraulic and fuel-system enquiries require different fluid and installation details:

• Hydraulic Systems: For pumps, valves, cylinders and fittings, provide oil grade, pressure, temperature, static or moving duty, gland dimensions and extrusion clearance. Review backup-ring requirements with the seal design.
• Fuel Systems: For fuel-transfer or equipment replacement enquiries, provide the fuel composition, additives, temperature and equipment reference. Confirm any application-specific approval requirements before selecting the compound.
• Industrial Machinery: Provide the lubricant, medium and seal dimensions for pneumatic tools, compressors or machinery maintenance. Match ID, cross-section and tolerances to the actual gland.

Material Comparison: NBR vs. Others

NBR vs. FKM (Fluorocarbon):
NBR and FKM are different material families. Compare the exact fluid, minimum and maximum temperature, exposure duration and required low-temperature flexibility against compound data rather than applying one universal temperature range.

NBR vs. EPDM (Ethylene Propylene):
EPDM is commonly considered for weather exposure and selected water-service requirements, while NBR is considered for many oil-service applications. Petroleum-fluid compatibility must be reviewed for the actual formulation; neither material is a universal substitute for the other.

Product Description

	Material: Nitrile Butadiene Rubber (NBR / Buna-N)
	Color: Black
	Hardness: 70-90 Shore A options; confirm target value and tolerance
	Tensile Strength: Confirm the selected compound specification and test requirement

Company Profile

Established in 2013, Shanghai Qinuo Industry (SHQN) specializes in the engineering and manufacturing of high-performance rubber seals for the Oil & Gas industry.

Our production base in Nantong is equipped with over 30 advanced vulcanizing machines, delivering a monthly capacity of 20 tons (40,000 lbs) across 20+ product categories. Strategically located near Shanghai’s major air and sea ports, we ensure streamlined logistics and reliable global delivery.

Under our registered brands Royal Way® and SHQN®, we remain committed to our core principle: "Quality for Stability, Innovation for Progress." We provide the energy sector with durable, precision-engineered sealing solutions you can depend on.

FAQ

Question: What is the typical shelf life of a Nitrile (NBR) O-ring?
Answer: Storage acceptance depends on the compound, manufacture date, packaging and applicable storage requirements. Keep rings protected from heat, light, ozone and deformation, and inspect them before installation. This listing does not guarantee a universal 15-year shelf life.

Question: Can I use Nitrile O-rings for outdoor applications?
Answer: NBR requires review for prolonged ozone and sunlight exposure. If outdoor weathering is significant, assess protection or an alternative compound together with the actual fluid. EPDM must not be substituted without checking oil and fuel compatibility.

Question: What is the difference between 70 Shore A and 90 Shore A hardness?
Answer: The higher Shore A value indicates a harder rubber. Select hardness with gland dimensions, clearance, pressure, temperature and movement; hardness alone does not establish the pressure rating of the seal assembly.

Question: Is it safe to reuse a Nitrile O-ring after a machine teardown?
Answer: Follow the equipment maintenance procedure. Removed rings may show compression set, cuts or fluid-induced changes, so replacement is generally preferable during planned teardown. Inspect the gland and select a correctly specified replacement.