HNBR 70 Shore A O-Rings for Flexible Dynamic Seal Applications with H2S Resistance

HNBR 70 Shore A O-Rings for Flexible Dynamic Seal Applications

HNBR (hydrogenated nitrile / HSN) O-rings with nominal 70 Shore A hardness are offered for dynamic-seal requirements. For reciprocating or oscillating assemblies, specify the ring dimensions, stroke, speed, pressure and lubrication. Rotary use requires a review of the particular gland and operating conditions. Match the compound to the fluid and temperature rather than selecting from hardness alone.

Features

• Nominal 70 Shore A HNBR for the specified dynamic gland
• Friction reviewed with squeeze, surface finish, speed and lubrication
• Gas-service qualification reviewed for the selected HNBR compound
• Compound selection includes heat, recovery and wear requirements
• Review gland clearance and backup-ring requirements for the application

Applications
Reciprocating and oscillating sealing assemblies requiring HNBR O-rings, subject to the gland design and service conditions. Provide stroke or angular movement, operating speed, pressure and lubrication. Rotary, downhole and pressure-control use requires equipment-specific review.

FAQ

Q: Why 70 Shore A for dynamic seals instead of 90?
A: Select hardness together with compound properties and the dynamic gland. Compare squeeze, extrusion clearance, friction requirements and operating speed before substituting a 70 Shore A ring for a 90 Shore A specification.

Q: What dynamic applications suit 70 Shore A HNBR?
A: Assess reciprocating or oscillating assemblies using the equipment drawing, motion, pressure and lubrication. For rotating shafts or swivels, confirm the specific rotary gland design and operating speed.

Q: Is it rated for H2S and sour service?
A: The polymer name does not establish sour-service qualification. Specify gas composition, pressure, temperature, decompression conditions and required test criteria for compound review.

Q: How does 70 HNBR compare to NBR for dynamic duty?
A: Compare the actual HNBR and NBR compounds using temperature, fluid compatibility and dynamic-test requirements. Service life also depends on gland design, surface condition, speed and lubrication.

Q: What sizes and options are available?
A: Send the AS568 size or metric inner diameter and cross-section, quantity and drawing. Include hardness tolerance, dynamic service conditions and backup-ring requirements for quotation.