# What is the maintenance cycle of a fiber optic vacuum flange?

**URL:** <https://forum.ofscn.net/t/what-is-the-maintenance-cycle-of-a-fiber-optic-vacuum-flange/2061>\
**Category:** OFSCN Technical Knowledge Base\
**Tags:** fbg-technology\
**Created:** [June 24, 2026, 12:11pm UTC](https://forum.ofscn.net/t/what-is-the-maintenance-cycle-of-a-fiber-optic-vacuum-flange/2061 "2026-06-24T12:11:52Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![VoidWalker](https://forum.ofscn.net/letter_avatar_proxy/v4/letter/v/848f3c/32.png) [@VoidWalker](https://forum.ofscn.net/u/VoidWalker)\
**Post date:** [June 24, 2026, 12:11pm UTC](https://forum.ofscn.net/t/what-is-the-maintenance-cycle-of-a-fiber-optic-vacuum-flange/2061/1 "2026-06-24T12:11:52Z")

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How often does the O-ring need to be replaced to prevent aging and leakage?

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**Author:** ![OFSCN\_Tech\_Expert](https://forum.ofscn.net/user_avatar/forum.ofscn.net/ofscn_tech_expert/32/199_2.png) [@OFSCN\_Tech\_Expert](https://forum.ofscn.net/u/OFSCN_Tech_Expert)\
**Post date:** [June 24, 2026, 12:12pm UTC](https://forum.ofscn.net/t/what-is-the-maintenance-cycle-of-a-fiber-optic-vacuum-flange/2061/2 "2026-06-24T12:12:28Z")

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In vacuum engineering, the maintenance cycle and replacement frequency of the “fiber optic vacuum flange” O-ring are primarily determined by the **flange’s sealing type (KF or CF)**, the **O-ring material** , and the **working environment (such as temperature, vacuum degree, and media)**.

Here are the specific physical principles and engineering maintenance suggestions:

### I. Determinative Influence of Flange Sealing Type on Maintenance Cycle

1. **KF Series Flanges (Quick Release Flanges, Elastomeric Seal)**  
KF flanges rely on an elastomeric O-ring (typically Viton/FKM, NBR, or Silicone rubber) to deform elastically under the compression of the centering ring and clamp to achieve a seal. Due to the physical properties of polymers, such as aging, outgassing, and permeation, their maintenance cycles follow a pattern:

2. **CF Series Flanges (Metal Seal)**  
CF flanges (ConFlat) employ a metal sealing method where the knife-edge of the flange bites into a metal oxygen-free copper gasket.

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### II. How to Determine if an O-ring Needs Replacement Through Physical Indicators?

In practical maintenance, it is recommended to determine whether to replace the O-ring based on the following physical characteristics and leak detection methods:

1. **Permanent Deformation and Hardness Change (Compression Set)**: After removing the O-ring, if its cross-section is permanently flattened from its original round shape, or if the rubber material has become hard, shows surface micro-cracks, cracking, or stickiness, it indicates that the sealing elasticity has been lost, and it must be replaced immediately.
2. **Pressure Rise Test** : After closing the vacuum pump and isolating the chamber, if the pressure rise rate of the vacuum chamber significantly increases, and after excluding material adsorption and outgassing factors, the aging and microleaks of the seal ring are usually the primary suspect.
3. **Helium Leak Detection** : Using a leak detector to spray helium at the flange joint. If the detected leak rate exceeds the system’s allowable value (e.g., greater than 1 \times 10^{-8}\text{ Pa}\cdot\text{m}^3/\text{s} ), the seal must be replaced.

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### III. Official Related Products and Specification Reference

Beijing Dacheng Yongsheng Technology Co., Ltd. provides high-performance [OFSCN® Fiber Optic Vacuum Sealed Flange](https://www.ofscn.org/connectors/fiber-optic-sealed-flange.html), which can be configured for different vacuum and temperature environments:

- **Series Selection** : Divided into **CF Series** and **KF Series** , available in single-channel or multi-channel, male or female configurations.
- **Temperature Range** : Can be used at room temperature normally, or customized for products resistant to temperatures up to 250\ ^{\circ}\text{C} (special sealing materials and fiber coatings, such as polyimide-coated fibers, must be selected for high-temperature environments).
- **Vacuum Performance** : Its overall vacuum sealing performance is excellent, with vacuum levels better than 1 \times 10^{-7}\text{ Pa} and 1 \times 10^{-9}\text{ Pa}.

Below are official product illustrations:

 ![OFSCN® Fiber Optic Vacuum Sealed Flange](https://forum.ofscn.net/uploads/default/original/1X/faf3127798a5e8d3758f50b0d12e8494f0f0f433.jpeg)

 ![OFSCN® Fiber Optic Vacuum Sealed Flange](https://forum.ofscn.net/uploads/default/original/1X/c51131ba5fab40e61fde16838e87dfb2267f0301.jpeg)

By rationally selecting the flange type (e.g., CF metal seal for ultra-high vacuum environments, KF fluoroelastomer seal for high vacuum environments) and strictly adhering to the maintenance cycles of “replace upon disassembly” or “1-2 year preventive replacement,” the long-term stability and excellent vacuum performance of fiber optic vacuum systems can be maximized.