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 (HSN) O-rings at 70 Shore A built for dynamic seals that need to follow a moving surface — reciprocating rods, rotating shafts, and oscillating joints. The softer 70 durometer flexes through each cycle with lower breakout and running friction than 90 Shore A, while still carrying HNBR's heat and sour-gas ratings that standard NBR cannot match.

Features

• 70 Shore A flexes with moving surfaces for stable dynamic sealing
• Lower breakout and running friction than 90 durometer HNBR
• Rated for H2S and CO2 sour service in oilfield duty
• Higher heat ceiling than NBR with better recovery and wear life
• Available with anti-extrusion back-ups for higher-pressure motion

Applications
Reciprocating hydraulic rods, rotating shaft seals, swivels and rotating heads, oscillating joints, downhole dynamic tools, top drives, and wellhead seals that see continuous motion with oil, heat, and often sour gas.

FAQ

Q: Why 70 Shore A for dynamic seals instead of 90?
A: Dynamic seals must follow a moving surface and flex every cycle. 70 Shore A is more compliant, gives lower breakout and running friction, and recovers better than 90. Use 90 where abrasion or extrusion dominates and the seal is mostly static or slow-moving.

Q: What dynamic applications suit 70 Shore A HNBR?
A: Reciprocating hydraulic rods, rotating shafts, swivels, oscillating joints, and downhole dynamic tools that see motion plus oil, heat, and often sour gas — the cases where flexibility matters more than maximum hardness.

Q: Is it rated for H2S and sour service?
A: Yes. HNBR is specified for H2S and CO2 environments. Give us the gas concentration and temperature so we select the compound and cure that fits the duty.

Q: How does 70 HNBR compare to NBR for dynamic duty?
A: HNBR lasts longer under heat and sour gas and resists wear better, while 70 Shore A keeps the flexibility a dynamic seal needs. For oilfield motion seals it typically outlasts NBR by a wide margin.

Q: What sizes and options are available?
A: Molded AS568 and ISO 3601 sizes are stocked, with custom HNBR blends and anti-extrusion back-up rings available for higher-pressure dynamic applications.