Back-up Rings at NewDealSeals
Back-up rings find their purpose in preventing the extrusion of O-rings into the diametrical clearance, ensuring a secure and reliable seal. At NewDealSeals, we offer a variety of back-up rings designed to cater to different application needs, including single-cut and spiral design rings for closed grooves and single solid designs for open grooves, recommended for the highest pressures.
What Are Back-Up Rings?
Back-up rings are indispensable components in sealing technology, tasked with a crucial mission: preserving the integrity of seals, particularly O-rings. These rings serve as protective barriers, preventing the extrusion of O-rings into the diametrical clearance. In essence, they ensure that seals perform their sealing function effectively, especially in dynamic and high-pressure applications.
When to specify Back-Up Rings:
We recommend considering back-up rings when one or more of the following working conditions are present, and the intention is to rely solely on O-rings for sealing:
- Pressure exceeding 50 bar.
- Diametrical clearance exceeding 0.25 mm at pressures exceeding 10 bar.
- High stroke frequency.
- Elevated temperatures.
- Contaminated medium.
- Significant pressure pulsations or frequent pressure changes.
Advantages of Back-Up Rings
Back-up rings unlock several advantages, including:
- The ability to handle pressures above 50 bar when used with O-rings.
- Accommodating larger diametrical clearances.
- Enhanced stability at high temperatures and during rapid pressure changes.
Types of movement and available materials
Back-up rings are versatile, suitable for dynamic reciprocating, dynamic rotating, and static applications. We offer back-up rings in a range of materials, including PTFE, POM, PCTFE, and PU, ensuring compatibility with diverse sealing needs.
Technical Specifications
Movement Type
Dynamic reciprocating/dynamic rotating, static
Available materials
PTFE, POM, PCTFE, PU
Back-up Ring profiles
PROFILE T1
For reciprocating movements
Consists as standard two spiral windings which are cut at the ends at an angle.
Compensation of large temperature changes and tolerances.
PROFILE T2
Preferred for internal sealing applications
Preferred for internal sealing applications when installed in closed grooves where uncut back-up rings are not suitable.
Reciprocating and rotating movements possible. Economic price level.
PROFILE T3
Reciprocating and rotating movements possible
A divisible groove is recommended for external sealing. Economic price level.
PROFILE T4
Preferred for internal sealing applications
Concave cross-section.
Reciprocating and rotating movements possible.
The large contact surface protects the O-ring against deformation in case of high pulsating pressure. Dimensional stability of the O-ring improves the sealing force and increases the service life.
PROFILE T5
Recommended for external sealing
Concave cross-section. Reciprocating and rotating movements possible.
The large contact surface protects the O-ring against deformation in case of high pulsating pressure.
Dimensional stability of the O-ring improves the sealing force and increases the service life.
PTFE COMPOUNDS
| Color | Temperature | Application | Information | |
|---|---|---|---|---|
| NDS-100 PTFE-virgin |
White | -190 to +230 °C | Chemical Industry, Food Industry | High chemical resistance Datasheet |
| NDS-123 PTFE +15% glass, +5% molybdenum disulfide |
Grey | -190 to +290 °C | Medium-duty | High chemical resistance, High creep resistance, Electrical properties like virgin PTFE Datasheet |
| NDS-225 PTFE +25% carbon |
Black | -190 to +315 °C | Pneumatics Rotary sealing | High wear and creep resistance Datasheet |
| NDS-235 PTFE +10% carbon fibre |
Black | -260 to +310 °C | Water hydraulics, Seawater, Short strokes with high frequency | Very good wear properties Datasheet |
| NDS-430 PTFE + 23% carbon + 2% graphite |
Black | -100 to +250 °C | Medium-duty, cold creep, thermal conductivity | Chemical and wear resistance Datasheet |
| NDS-555 PTFE + mineral fibers |
Antrachite | -200 to +260 °C | Medium and heavy mechanical stress, Hydraulic applications | Chemical, wear and creep resistance Datasheet |
| NDS-640 PTFE +40% bronze |
Bronze | -156 to +260 °C | Medium and heavy mechanical stress, Hydraulic applications |
Outstanding wear and creep resistance
|
| NDS-660 PTFE +60% bronze |
Bronze | -156 to +260 °C | Heavy mechanical stress, Hydraulic applications | Outstanding wear and creep resistance |
| NDS-750 PTFE + polyimide |
Tan | -260 to +310 °C | High speed rotating applications | Use against soft metals |
Related PTFE Seals
CONTACT FORM
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NewDealSeals B.V.
+31 (0) 226 362 233
Boezemschop 8, Breekland, 1724 BJ Oudkarspel, The Netherlands