MKS 292138 Bellows Vacuum Hose KF25 NW25 SS321/304

( Brand: Mks ), ( Manufacturer Part Number: 292138 ), ( Type: Bellows Hose Metal ), ( Unit Type: Unit )

Review MKS Inch Stainless Bellows Vacuum Hose Ss321/304

The **MKS Instruments 292138 KF25 NW25 20 Bellows Vacuum Hose (SS321/304)** is a high-performance, precision-engineered vacuum transfer line designed for demanding applications in scientific research, semiconductor manufacturing, and industrial process control. Constructed from **316L or 321 stainless steel** (available upon request), this bellows hose combines exceptional durability with superior flexibility, making it ideal for environments where contamination resistance, corrosion protection, and reliable sealing are critical. The **KF25 (Konus-Flansch) male-to-male** connection ensures a secure, leak-tight interface with minimal dead volume, while the **NW25 (Normwerk) female-to-female** end provides versatility for integration with a wide range of vacuum systems, including mass spectrometers, gas analyzers, and ultra-high-vacuum (UHV) chambers. With a **20-inch (508 mm) length**, the hose offers just enough flexibility to accommodate dynamic motion or repositioning without compromising structural integrity, thanks to its **metallic bellows design**, which absorbs vibration and thermal expansion while maintaining a consistent internal diameter for optimal flow characteristics. The **321 stainless steel** variant, in particular, is engineered to withstand elevated temperatures and resist intergranular corrosion, making it suitable for applications involving aggressive chemicals or high-temperature processes. Whether used in ultra-pure environments or high-vacuum systems, this hose delivers a seamless, contamination-free transfer of gases or liquids while minimizing outgassing and maximizing system efficiency. Its robust construction and precision machining ensure long-term reliability, reducing the need for frequent replacements and minimizing downtime in critical operations.

### **Pros and Cons of Buying MKS 292138 KF25 NW25 20 Bellows Vacuum Hose (SS321/304)**

1. **High-Purity Stainless Steel Construction** Made from **321 or 304 stainless steel**, this hose is resistant to corrosion, oxidation, and contamination, making it ideal for **semiconductor, pharmaceutical, and cleanroom applications** where purity is critical.

2. **Bellows Design for Flexibility and Durability** The bellows construction allows for **flexible movement** while maintaining a **sealed connection**, reducing wear and tear compared to rigid or braided hoses. This design also helps prevent **vibration-induced fatigue** and **leakage** over time.

3. **KF25 Flange Compatibility** The **KF25 (Konus Flansch)** connection is a **standard in high-vacuum systems**, ensuring compatibility with **MKS, Leybold, Edwards, and other vacuum equipment**. This makes it easy to integrate into existing setups without additional adapters.

4. **High-Vacuum Performance** The **NW25 (Nominal Working Vacuum)** rating indicates it can handle **ultra-high vacuum (UHV) and high-vacuum applications**, typically down to **10 to 10 Torr**, depending on system configuration.

5. **Chemical Resistance** Stainless steel (especially **321 with titanium stabilization**) resists **acidic and alkaline environments**, making it suitable for **etching, sputtering, and plasma processing** applications.

6. **Long Lifespan** The **bellows design and stainless steel** reduce wear, extending the hose s operational life compared to rubber or silicone alternatives.

7. **Cleanability** Unlike some elastomeric hoses, stainless steel can be **sterilized and cleaned** with **chemicals, steam, or UV light**, which is essential in **pharma and biotech** applications.

8. **Temperature Resistance** Stainless steel hoses can withstand **wide temperature ranges** (typically **-250 C to 400 C**), making them versatile for **cryogenic to high-temperature** applications.

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1. **Higher Cost Compared to Alternatives** Stainless steel bellows hoses are **more expensive** than **rubber, silicone, or braided metal hoses**, which may be sufficient for **low-vacuum or non-critical applications**.

2. **Limited Flexibility in Extreme Bends** While the bellows design allows movement, **excessive bending or twisting** can cause **fatigue and leakage** over time, requiring careful installation.

3. **Weight** Stainless steel hoses are **heavier** than polymer or braided metal alternatives, which may complicate **portable or mobile vacuum systems**.

4. **Potential for Metal Contamination** In **ultra-high-purity applications**, even trace **stainless steel particles** (from wear or corrosion) can be problematic. Some systems may require **additional filtration** to mitigate this risk.

5. **Specialized Installation Requirements** KF flanges require **proper sealing with PTFE tape or vacuum grease** to prevent leaks. Improper installation can **compromise vacuum integrity**.

6. **Not Ideal for High-Pressure Applications** While strong in vacuum, these hoses are **not designed for high-pressure gas delivery** (e.g., compressed air), which could cause **bellows collapse or failure**.

7. **Limited Availability of Replacement Parts** If the hose fails, **finding exact replacements** (especially for older or discontinued models) may be difficult compared to more common hose types.

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The **MKS 292138 KF25 NW25 20 bellows vacuum hose (SS321/304)** is a **premium choice** for **high-vacuum, cleanroom, and high-purity applications** where **corrosion resistance, flexibility, and long-term reliability** are critical. Its **stainless steel construction, bellows design, and KF flange compatibility** make it superior for **semiconductor manufacturing, pharmaceutical processing, and scientific research**.

However, if **cost, weight, or simplicity** is a priority, alternatives like **braided metal hoses, silicone hoses (for moderate vacuum), or KF rubber hoses** may be more suitable for **lower-vacuum or non-critical applications**.

- You need a **high-vacuum, corrosion-resistant, and long-lasting** solution.

- Your application involves **semiconductor fabrication, pharmaceutical processing, or UHV environments**.

- You require **flexibility without leakage** in critical systems.

- You are working with **low-vacuum or non-critical applications** where cost is a major factor.

- You need **higher pressure resistance** or **easier handling** (e.g., lighter weight).

- You require **disposable or low-cost hoses** for temporary setups.

For most **high-end vacuum systems**, this hose is a **strong, reliable investment** worth the higher cost. Always verify **compatibility with your specific vacuum pump and system** before purchasing.

Details:

length : approx. No visible cracks, holes, or structural damage. Size: KF25 / NW25. Bellows remain flexible and intact.

Application: Ideal for vacuum systems, laboratory setups, semiconductor equipment, and industrial use. Part Number: 292138. Shipping: Carefully packed and shipped promptly. Condition: Used in good condition.

Shows normal cosmetic discoloration from prior use. Material: SS321/304 stainless steel. Genuine MKS stainless steel vacuum bellows hose with KF25 NW25 flanges. Fully functional and ready for installation.

Flexible bellows design for vibration isolation and alignment. Includes: Exactly what is shown in the photos.

part #: 292138 prices

• $69.99-$99.00

specifications valvplu:

• brand: Mks
• mpn: 292138
• type: Bellows Hose Metal
• unit type: Unit

returns valvplu:

• policy: No Returns

payments valvplu:

• credit card: Diners-club
• other
• wallet: Paypal

seller valvplu:

• rating: 96.8%
• # reviews: 228
• city: Tarpon Springs, Florida

shipping valvplu:

• transit: 5-12 Days
• carrier: USPS
• service: USPS Ground Advantage
• cost: $11.01
• type: Calculated
• class: Standard

general valvplu:

• condition: Used
• Pumps Pump Accessories > Vacuum Pumps > Other Vacuum Pumps

offer valvplu:

• availability: In Stock
• options: Ship-to-home
• started: April 22, 2026
• best offers: True
• sold: 0
• quantity: 2

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