A rubber backup ring (also known as an anti-extrusion ring) is not a primary sealing element but an auxiliary component used to protect the main seal (e.g., an O-ring). Its core function is to prevent the seal from being extruded into the mating clearance under high pressure, which would otherwise cause damage.

The need for a backup ring depends mainly on the working pressure, temperature, and clearance. General guidelines:

Pressure threshold – When the system pressure exceeds 10 MPa, a backup ring should generally be considered.
High-temperature effects – At temperatures above 100 °C, even pressures below 10 MPa may require a backup ring.
Dynamic seals – For moving seals (e.g., reciprocating motion), the pressure threshold is usually lower than for static seals.

Extrusion prevention – Under high pressure, soft seals like O –rings tend to be forced into the gap between mating parts. The backup ring fills this gap and acts as a "stop" or "backup".
High –pressure capability – With a backup ring installed, the sealing system can withstand significantly higher pressures than an O –ring alone. For example, an O –ring without a backup ring is typically limited to about 20 MPa, whereas with a backup ring it can handle 40 MPa or even more.
Extended service life – By preventing extrusion, twisting, tearing, and other damage to the O –ring, the backup ring greatly prolongs its operational life.

Position – The backup ring must be installed on the side opposite to the pressure source relative to the O–ring. If pressure may act from both sides, a backup ring should be placed on each side of the O–ring.
Dimensional fit – The backup ring's dimensions must be precisely matched to the O–ring and groove. Common cross–sectional diameters (widths) range from 1.5 mm to 10 mm.

Q 1. What's the payment term?
A: We accept T/T 50% advance ,   50% balance before booking shipping date.

Q 3. What is your standard packing?
A: All the goods will be packed by carton box and loaded with pallets. Special packing method can be accepted when needed.

Q 4. Could you please tell us the month capacity of your products ?
A: It depends on which model, we produce more than 500 tons rubber materials per month.

Q 5. what kind of certificates you have ?
A1: We have been ISO9001:2015 and ISO14001:2004 certified by SGS since 2015.
A2: We have various rubber compounds approved by ROHS and REACH.

Q6: How to check the quality of the bulk order?
A1: We provide preproduction samples before mass production for all customers if needed.
A2: We accept third party inspection such as TUV, INTERTEK, BV, etc.

Q 7: Do you use any international standards for the rubber products?
A: Yes, we mainly use GB/T3452.1-2005 standard to define the quality of the rubber materials.

Q8: What materials are available to produce from your side?
A: NBR, EPDM, SILICONE, FPM(FKM), PTFE,POM,PU,NEOPRENE(CR), NR, IIR, SBR, ACM, AEM, Fluorosilicone(FVMQ), FFKM, Liquid Silicone, Sponge, etc.

Q9: Do you provide maintenance on tooling?
A: We maintain all tooling and will replace as needed.

Q10: How many empolyees you have?
A:We have 25 empolyees at time of December 2024.

Customer can choose 4ways for get the goods.

NINGBO PALT IMPORT AND EXPORT CO.,LTD (The factory name is Huan Ling Sealing  )the products including the O-rings, Flat washer, rubber rings, ED-Ring,Bonded seal,PTFE rings, O-ring Kit,rubber ball, Y-rings,Rubber Strip,Piston U-seal,Rod U-seal,Glyd-Ring,Sitefeng seals, v-shaped rings, X-rings and other various non-standard rubber.In addition,The main material can be NBR, EPDM, FKM, , AFLAS, CR, Butyl, HNBR, SILICON, FFKM, PU or approved by  etc.

Huan Ling Sealing has the product is made of imported raw materials, quality excellent, the company products have been exported to Europe and the United States, the feedback is good, is a broad seal users trustworthy company.

Huan Ling Sealing established in 2011. Huan Ling Sealing is a professional rubber products manufacturer .Business involves the engineering machinery, plastic machinery, hydraulic press, compressor, die-casting machine, ceramic machinery, port machinery, metallurgical machinery, steel, steamboat manufacturing, coal mine machinery, chemical machinery, light industry machinery, mining machinery and machine tools, and other fields and industries.