Σφραγισμένη βαλβίδα σφαιρικής φυσούνας | ΠΝ16-ΠΝ40 | Μηδενική διαρροή | Ατμός & Υπηρεσία υψηλών θερμοκρασιών

Product Overview

ΟΣφραγισμένη βαλβίδα σφαιρικής φυσούνας is a high-performance industrial valve designed for applications wherezero 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 ametal bellows assembly as the primary stem seal, creating a permanent barrier between the process fluid and the atmosphere.

The bellows sealed globe valve is thepreferred 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 deliversmaintenance-free operation and significantlyreduces energy loss caused by leakage.

The valve body is available inWCB cast steel καιανοξείδωτο χάλυβα, with sealing faces hardfaced withCoCr alloy for extended service life. The stem is subjected tonitriding treatment for enhanced wear and corrosion resistance. The valve complies withAPI 623, ΑΠΟ 3356, καιGB/T 12235 πρότυπα.

Σφραγισμένη βαλβίδα σφαιρικής φυσούνας

Working Principle

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

When the discapproaches the seat → flow area decreases → flow is throttled

When the discmoves away from the seat → flow area increases → flow is permitted

Οcritical innovation is themetal 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 bellowscompress and expand with negligible friction, maintaining aστεγανή σφράγιση without any sliding gaps.

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

The valve features aback 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

Σφραγισμένη βαλβίδα σφαιρικής φυσούνας

Key Features

• 1. Zero Stem Leakage
  The metal bellows provides apermanent, 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)
  ΕΝΑsecondary 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 for3,000+ κύκλους in standard service. The sealing faces are hardfaced withCoCr alloy and precision ground, providing exceptional wear resistance and long-term reliability.
• 4. Energy Savings & Προστασία του Περιβάλλοντος
  By eliminating fugitive emissions, the valvereduces energy loss καιprevents 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, significantlyreducing maintenance costs and downtime.
• 6. Stem Nitriding Treatment
  The valve stem is subjected tonitriding treatment, enhancing surface hardness, wear resistance, and corrosion resistance for extended durability.
• 7. Visual Position Indicator
  The valve features anintuitive 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 preventstorsion of the bellows during operation, extending bellows life and ensuring reliable sealing.

Εφαρμογές

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

Key Media Compatibility:

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

Bellows Sealed vs. Conventional Globe Valve

Packaging & Shipping

Payment Methods

T/T, L/C εν όψει, Western Union, PayPal, Credit Card, και τα λοιπά.

Εταιρικό Προφίλ

Luoyang Datang Energy Tech Co., Ε.Π.Ε. 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, βαλβίδες σφαίρας, σφαιρικές βαλβίδες, βαλβίδες πεταλούδας, 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, ΑΠΟ, and GB. Our technical team is available to provide selection guidance, application engineering support, and after-sales service.

Σφραγισμένη βαλβίδα σφαιρικής φυσούνας

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 fromPN16 to PN40 (1.6MPa – 4.0MPa). For higher temperature or pressure applications, please consult our technical team for special material options.

Ε2: What makes a bellows sealed globe valve different from a standard globe valve?

English: The key difference is themetal bellows that replaces the conventional packing as the primary stem seal. This eliminates the dynamic sealing gap between the stem and bonnet, providingzero 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.

Ε3: Can this valve be used for throttling/regulating service?

English: Ναί. As a globe valve, it isinherently 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 thebalanced disc option to reduce operating torque.

Q4: What is the expected bellows service life?

English: The bellows is designed for3,000+ operating cycles in standard service. The actual service life depends on operating conditions including temperature, πίεση, 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 withAPI 623 (design standard for globe valves), MSS SP-117 (bellows seal standard), ΑΠΟ 3356 (German standard), καιGB/T 12235 (Chinese national standard). It is alsoSIL 3 ready for functional safety applications and can be supplied withISO 15848 certification for fugitive emissions.