High Performance X‑Ring Four Lips Seal NBR FKM FFKM Quad Ring For Reciprocating Motion

The X-ring is a symmetrical 4 lobe seal, with a square fitting cross section. It is similar to 4 tangent O-Rings. The inner diameter (I.D) and the width of the cross section (C.S.) are the dimensional characteristics of the X-ring. These can be used instead of an O-ring but have a larger range of applications. They conform to US standard AS 568 A and can on request be delivered in alternative sizes and different materials: NBR,FKM, FFKM, EPDM, Silicon.

Because of its symmetrical shape, the X-ring can withstand any stress from any direction. An increase in pressure leads to a radial section increase and then to a progressive constraint of the seal.

Item	X‑Ring	O‑Ring
Cross‑section	X‑shape, four sealing lips	Circular single‑lip
Spiral twist failure	Resistant, almost no spiral damage	Easy to happen in long‑stroke reciprocation
Friction	Lower, smaller contact area; lip groove holds lubricant	Higher friction, full‑circle contact
Sealing redundancy	Double sealing lines, better reliability	Single sealing line
Recommended use	Reciprocating, oscillating, low‑speed rotary; high‑cycle dynamic conditions	General static sealing, simple low‑cycle dynamic applications
Groove compatibility	Fits AS568 O‑ring grooves; avoid minimum‑tolerance groove width	Designed for AS568 standard gland

Due to the "X" shape and the four sealing edges, X-rings require less initial compression compared to O-rings, resulting in reduced friction and thus wear in dynamic applications. Other advantages are:

● Square cross-section prevents rotation of the seal in the groove during assembly or straight-line movement.
● lower initial compression in dynamic applications reduces friction and wear, reducing the effect of permanent deformation and thus extending service life
● lubricant is trapped in the space created between the cutting edges, which aids perfect lubrication of the cutting edge during reciprocating straight-line motion, or during rotary or combined motion
● the cutting plane of the mould passes through the space between the blades and its quality cannot affect the function of the seal
● Similar to O-rings, simple and space-saving design, easy installation