Chengxin Industrial Seal King

Backup Ring | O-Ring Support for High-Pressure Seals

Is the O-ring being squeezed out of the gap under high pressure, causing the edges to be nicked, and resulting in repeated oil leaks from the equipment? Please send photos of the old part and the groove. Chengxin will first examine the direction of pressure, the sealing gap, and the specifications of the existing O-ring, and then respond with the types of retaining rings that can be discussed and the dimensions needed for replacement.
Send a photo of the old part to confirm the retaining ring type.
Faced Challenges

Have you encountered these three situations when working with high-pressure seals?

When the pressure increases, is the O-ring being forced into the gap between parts, causing its edges to be nicked or repeated oil leaks?
The existing retaining ring does not match the groove dimensions, and even after assembly, it still cannot provide stable support for the O-ring?

When all that’s left are worn-out old parts or equipment drawings, how can we determine the material, opening type, and dimensions of the retaining ring?

Backup Ring

Let Xin Seal King help you

First, determine on which side the O-ring was crushed, then compare the groove, sealing clearance, and assembly path to narrow down the options for retaining ring type and material. After receiving photos of the old part, drawings, and operating conditions, Chengxin will respond with the required dimensions and the feasibility of manufacturing or supplying the part.

Five Key Points Confirmed with Chengxin’s Assistance

Cheng Xin systematically assessed which side the O-ring would be extruded from, whether the groove could accommodate a retaining ring, the assembly path, and the material specifications. These five steps were used to narrow down the range of types and sizes.

01.

Confirm the extrusion position

Examine the location of damage on the old part, the direction of pressure, and the fit clearance to first determine which side the retaining ring should support.

02.

Check the Grooves and Dimensions

Based on the drawings, the O-ring cross-section, and the groove dimensions, determine the inner and outer diameters, thickness, and installation clearance of the retaining ring.

03.

Evaluation of Retaining Ring Types

Depending on the mounting method, options include full-circle, open-ended, or other processed configurations; the actual selection should be based on the drawings and operating conditions.

04.

Materials and Processing Discussion

Evaluate materials and the feasibility of machining according to drawings based on medium, temperature, pressure, and dimensional requirements.

05.

Confirm Inspection and Documentation Requirements

If you need dimensional inspections, material documentation, or batch information, please include these requests in your inquiry so we can confirm which items we can provide.

Backup Ring Types

First, consider the installation and compression directions; then, determine the retaining ring type based on the groove, dimensions, and operating conditions. The following are guidelines for inquiries; supply and machining must be confirmed on a case-by-case basis.
Schematic Diagram of the AI-Type Full-Circle Retaining Ring

Full-Circle Retaining Ring

Suitable for structures that can be assembled sequentially; verify the groove clearance, O-ring size, and direction of compression.

AI Type Diagram; actual shape and dimensions are subject to the drawings.

Schematic Diagram of the AI-Type Open-End Retaining Ring

Open-End Retaining Ring

Used in situations where assembly paths must be taken into account; the shape of the opening and the clearance are determined based on the drawings and operating conditions.

AI Type Diagram; actual shape and dimensions are subject to the drawings.

Schematic Diagram of an AI-Type Retaining Ring Manufactured to Drawing Specifications

Custom-Made Retaining Rings

Please provide old parts, drawings, or key dimensions so we can discuss the feasibility of special dimensions, materials, and machining.

AI Type Diagram; actual shape and dimensions are subject to the drawings.

Applications of Retaining Rings and O-Rings

The retaining ring is used to support the O-ring on the side of the sealing gap. Determine whether extrusion has occurred based on the location of the damage, the direction of pressure, and the groove dimensions, and then verify the assembly method. For the following six equipment scenarios, please take photos of the old parts and provide the relevant data.

Hydraulic and Pneumatic Systems

Is there an oil leak from the hydraulic cylinder after pressure is applied, and are there nicks on the edge of the O-ring? Take photos of the damaged area and the groove, including the direction of pressure and dimensions, to first determine if there is any extrusion.

Automotive and Transportation Industry

When disassembling or repairing automotive hydraulic or pneumatic assemblies, if the old O-ring is damaged on the clearance side, please provide the part drawing, the dimensions of the original part, and the working medium to confirm the retaining ring clearance specified in the original design.

Semiconductor and Electronics Industry

If the drawings for precision equipment specify the location of retaining rings, please indicate the medium with which they will come into contact, the cleanliness requirements, and the groove dimensions, and verify the material specifications and machining conditions.

Food and Pharmaceutical Industries

If a seal assembly needs to be replaced in a liquid-handling pump or valve, please provide the contact points, the cleaning medium, and the required compliance documents, and then confirm the material of the retaining ring and the supply specifications.

Petrochemical and Chemical Industries

If a pump or valve begins to leak after pressure is increased, please take a photo of the side where the O-ring is damaged and provide information on the medium, temperature, and pressure direction to verify the position of the retaining ring and the material specifications.

Water Treatment and Environmental Engineering

When removing a damaged O-ring during pump repair, please take a photo of the groove and the old part, along with details of the immersion medium and pressure conditions, to verify the replacement size and the clearance for the retaining ring.

How to Choose the Right Material for Retaining Rings

The material for the retaining ring must be evaluated in conjunction with the O-ring, pressure, clearance, medium, and temperature. The following lists potential engineering materials for consideration; specific grades, filler formulations, dimensions, and availability will be confirmed based on the drawings and operating conditions.

PTFE / Filled PTFE

Common material orientations for retaining rings. Filler formulations can be discussed based on pressure, wear, and medium conditions, and assembly methods and dimensions should be verified.

PEEK

Consider this option when higher rigidity and dimensional stability are required; actual applicability must be verified based on the medium, temperature, and clearance.

PCTFE

Although evaluation can be based on low-osmolarity and size criteria, operating conditions and supply specifications must still be verified.

PVDF

Material selection should be based on an evaluation of media compatibility and processing dimensions, and must be tailored to the actual temperature, pressure, and stress conditions.

PI and other engineering plastics

For special temperature or dimensional requirements, other engineering plastics may be considered; specific grades and processability will be determined on a case-by-case basis.

Material Grade and Supply Confirmation

For PTFE-filled formulations and other engineering plastics, compare the available grades, machinable dimensions, and assembly methods to confirm the deliverable specifications.

If you have any old parts or drawings, we can start the discussion; any missing information can be provided item by item as we communicate.

Please forward these three items; Cheng Xin will make an initial assessment first.

You can get started with photos of the old part; drawings and operating conditions can be added as more information becomes available. Cheng Xin should first mark the dimensions that need to be confirmed and the direction of the load.

① Used parts and photos: Take photos of the O-rings, retaining rings, and grooves, and mark the locations of any damage or extrusion.

② Drawings and Dimensions: Indicate the cross-section of the O-ring, the inner and outer diameters of the groove, the depth, and the fit clearance; provide known values first.

③ Operating Conditions: Specify pressure and direction, medium, temperature, whether for reciprocating or static use, and the required quantity.

After sending the data, what will Chengxin reply?

01Preliminary Data Analysis

Response regarding the side of the damage as initially assessed, as well as the photos and dimensions that still need to be confirmed

02Specification Verification

List the specifications for O-rings, grooves, and the compression direction that still need to be verified

03Manufacturing and Delivery Times

Once the specifications and quantities are finalized, we will respond with information on supply or processing feasibility, a quote, and delivery times.

04Assembly Discussion

Identify the space and orientation to be considered for full-circle or open-ended assemblies

05Delivery Confirmation

Confirm the items available for size verification and material documentation upon order confirmation

Take Immediate Action

Send photos of the old parts to receive a list of dimensions to be replaced

Start by reviewing photos of the old part to determine the required dimensions and discuss possible designs; once all specifications are finalized, confirm the quote and delivery date.

First, let's look at the old parts and drawings.

Determine the location of the damage to the O-ring, the groove, and the measurable dimensions.

Discussion Format and Materials

Evaluate the design of retaining rings based on the direction of pressure, the medium, and the installation space.

Confirm the Quote and Delivery Schedule

Once the specifications, quantity, and delivery terms have been confirmed, we will respond with a quote and delivery schedule.
Are you ready to get started?

Please send us photos of the old part first, and we'll help you figure out the next steps.

Send a photo of the old part to confirm the retaining ring type.