X-Ring, Quad-Ring, Q-Ring Seals – Reliable High-Pressure Sealing

What is an X-Ring or Quad-Ring?

An X-ring seal, also known as a Quad-ring or Q-ring, features an X-shaped cross-section that provides double sealing contact compared to standard O-rings. This design makes X-rings especially effective in high-pressure sealing applications, both static and dynamic.

Where are X-Rings Used?

X-rings are widely used in hydraulic and pneumatic systems, piston rods, pumps, high-pressure valves, and anywhere O-rings of 80 or 90 ShA hardness fail. Their structure supports long-term performance in dynamic rotary applications.

Why Choose an X-Ring for High Pressure?

The X-profile creates two sealing lines, offering greater surface contact and balanced stress distribution, which extends the life of both the seal and the equipment. This makes X-rings ideal for piston seals, rod seals, and dynamic shaft sealing.

Available X-Ring Materials from POWER Rubber

X-Ring in NBR (Nitrile)

Temperature range: -40 °C to +90 °C

Chemical resistance:

• Limited ozone and UV resistance

• High tear strength

• Short-term resistance to fuels and oils

• Suitable for aliphatic hydrocarbons

• Works with HSA, HSB, and HSC hydraulic fluids

• Resists mild acids and bases at low temperatures

X-Ring in FKM (Viton®)

Fluoroelastomer with temperature range: -25 °C to +210 °C

Resistance properties:

• Excellent compatibility with oils, greases

• UV and ozone resistant

• Resists acids: sulfuric, hydrochloric, nitric, phosphoric

• Compatible with chlorinated hydrocarbons, flame-resistant fluids

X-Ring in EPDM

Ideal for water-based and steam applications, -40 °C to +110 °C (up to 150 °C)

EPDM chemical resistance:

• Excellent resistance to weather, ozone, and UV

• Compatible with hot water, steam, and glycol-based brake fluids

• Resists both organic and inorganic acids

• Resistant to alkaline solutions (sodium, potassium)

• Compatible with phosphate ester hydraulic fluids, silicone-based oils

• Stable with Skydrol, ketones, esters, and alcohols

X-Ring vs O-Ring – What’s the Difference?

Our customers often ask: Should I use an X-ring or an O-ring?

Key differences:

• O-rings have a round cross-section

• X-rings have a cross-shaped profile

The X-ring provides more contact area, resulting in better sealing under dynamic stress. Additionally, X-rings offer improved longevity but are available in fewer material types and hardness levels than O-rings.

Need help choosing the right seal? Contact POWER Rubber for expert advice and custom quotes.