Bellows Sealed Globe Valve | PN16-PN40 | Zero Leakage | Steam & High-Temp Service

Product Overview

The Bellows Sealed Globe Valve is a high-performance industrial valve designed for applications where zero stem leakage is critical. Unlike conventional globe valves that rely solely on packing seals—which degrade over time and lead to fugitive emissions—this valve incorporates a metal bellows assembly as the primary stem seal, creating a permanent barrier between the process fluid and the atmosphere.

The bellows sealed globe valve is the preferred solution for steam systems, high-temperature thermal oil circuits, toxic or flammable media, and applications subject to strict environmental emission regulations. With a robust construction and dual sealing design (bellows + packing), this valve delivers maintenance-free operation and significantly reduces energy loss caused by leakage.

The valve body is available in WCB cast steel and stainless steel, with sealing faces hardfaced with CoCr alloy for extended service life. The stem is subjected to nitriding treatment for enhanced wear and corrosion resistance. The valve complies with API 623, DIN 3356, and GB/T 12235 standards.

Bellows Sealed Globe Valve

Working Principle

The bellows sealed globe valve operates on the linear motion principle common to all globe valves. Turning the handwheel rotates the stem, which moves the disc perpendicularly toward or away from the stationary seat ring.

When the disc approaches the seat → flow area decreases → flow is throttled

When the disc moves away from the seat → flow area increases → flow is permitted

The critical innovation is the metal bellows—an accordion-like stainless steel tube welded to the stem at the lower end and to the bonnet at the upper end. As the stem moves linearly, the bellows compress and expand with negligible friction, maintaining a leak-proof seal without any sliding gaps.

This design completely eliminates the dynamic sealing gap between the stem and the bonnet—the primary leak path in conventional packing-sealed valves. The bellows is backed by a secondary graphite packing seal, ensuring zero leakage even in the unlikely event of bellows failure.

The valve features a back seat mechanism that provides an additional stem seal when the valve is fully open, further enhancing safety during maintenance.

Technical Specifications

Valve Body Parameters

Material Options

Design & Manufacturing Standards

Bellows Sealed Globe Valve

Key Features

• 1. Zero Stem Leakage
  The metal bellows provides a permanent, non-wearing seal between the stem and the bonnet. Unlike packing that requires periodic adjustment and replacement, the bellows maintains leak-tight integrity throughout the valve’s service life.
• 2. Dual Sealing Design (Bellows + Packing)
  A secondary graphite packing serves as a backup seal. Even in the unlikely event of bellows failure, the packing prevents any leakage to the atmosphere, ensuring fail-safe operation.
• 3. Extended Service Life
  The bellows is designed for 3,000+ cycles in standard service. The sealing faces are hardfaced with CoCr alloy and precision ground, providing exceptional wear resistance and long-term reliability.
• 4. Energy Savings & Environmental Protection
  By eliminating fugitive emissions, the valve reduces energy loss and prevents product loss, contributing to lower operating costs and compliance with strict environmental regulations.
• 5. Maintenance-Free Operation
  The robust bellows seal design eliminates the need for periodic packing adjustment or replacement, significantly reducing maintenance costs and downtime.
• 6. Stem Nitriding Treatment
  The valve stem is subjected to nitriding treatment, enhancing surface hardness, wear resistance, and corrosion resistance for extended durability.
• 7. Visual Position Indicator
  The valve features an intuitive stem lift position indicator, allowing operators to easily verify whether the valve is open or closed.
• 8. Non-Rotating Stem Design
  The non-rotating stem prevents torsion of the bellows during operation, extending bellows life and ensuring reliable sealing.

Applications

The bellows sealed globe valve is the preferred choice for applications where zero leakage is non-negotiable—particularly in steam systems, hazardous media handling, and high-temperature industrial processes.

Key Media Compatibility:

• Steam & Condensate
• Thermal Oil
• Toxic & Flammable Fluids
• High-Purity Gases & Liquids
• Water
• Compressed Air & Other Gases

Bellows Sealed vs. Conventional Globe Valve

Packaging & Shipping

Payment Methods

T/T, L/C at sight, Western Union, PayPal, Credit Card, etc.

Company Profile

Luoyang Datang Energy Tech Co., Ltd. is a professional supplier of industrial valves and piping system solutions. With years of experience in the industrial flow control industry, we are committed to providing high-quality products and technical support to customers worldwide. Our product range includes gate valves, globe valves, ball valves, butterfly valves, bellows sealed valves, and actuated valves for various industrial applications.

We maintain strict quality control throughout the manufacturing process and ensure that all products meet international standards including API, DIN, and GB. Our technical team is available to provide selection guidance, application engineering support, and after-sales service.

Bellows Sealed Globe Valve

FAQ

Q1: What is the maximum temperature and pressure rating for this valve?

English: The valve is rated for temperatures from -29°C to +425°C and pressure classes from PN16 to PN40 (1.6MPa – 4.0MPa). For higher temperature or pressure applications, please consult our technical team for special material options.

Q2: What makes a bellows sealed globe valve different from a standard globe valve?

English: The key difference is the metal bellows that replaces the conventional packing as the primary stem seal. This eliminates the dynamic sealing gap between the stem and bonnet, providing zero leakage to the atmosphere. While standard globe valves rely solely on packing that degrades over time, bellows sealed valves offer maintenance-free operation and significantly longer service life.

Q3: Can this valve be used for throttling/regulating service?

English: Yes. As a globe valve, it is inherently designed for throttling and flow regulation. The disc moves perpendicularly to the seat, allowing precise control over flow rate. For applications requiring frequent throttling, we recommend selecting the balanced disc option to reduce operating torque.

Q4: What is the expected bellows service life?

English: The bellows is designed for 3,000+ operating cycles in standard service. The actual service life depends on operating conditions including temperature, pressure, cycling frequency, and media characteristics. The double-ply bellows construction provides enhanced reliability, and the non-rotating stem design prevents torsion damage to the bellows.

Q5: What standards does this valve comply with?

English: The valve complies with API 623 (design standard for globe valves), MSS SP-117 (bellows seal standard), DIN 3356 (German standard), and GB/T 12235 (Chinese national standard). It is also SIL 3 ready for functional safety applications and can be supplied with ISO 15848 certification for fugitive emissions.