Triple-Eccentric Multi-Layer Sealed Butterfly Valves and Metal Hard-Sealed Butterfly Valves: Reliable Shut-Off Solutions for High-Temperature and High-Pressure Service

Challenges of High-Temperature and High-Pressure Piping

High-temperature and high-pressure piping is a major challenge in industrial fluid control. The sealing surfaces are prone to wear. Leakage may occur after thermal deformation. The sealing structure can also be damaged by the process medium. These problems have long affected the stable operation of oil and gas, thermal power, metallurgical, and marine projects. Triple-eccentric multi-layer sealed butterfly valves and triple-eccentric metal hard-sealed butterfly valves are two types of high-performance butterfly valves. They adopt different sealing structures and can reliably shut off the fluid inside the pipeline under harsh operating conditions.

Common Structural Features

Both types of butterfly valves adopt a triple-eccentric design. The valve features eccentric offset in axial, radial and conical directions. When the valve opens and closes, the sealing surfaces do not rub against one another. The sealing surfaces make contact only when the valve is fully closed. This greatly reduces wear on the sealing interface and extends the valve service life. Both valves deliver bubble-tight bidirectional sealing. They can also withstand reverse pressure.

Features of Triple-Eccentric Multi-Layer Sealed Butterfly Valves

The triple-eccentric multi-layer sealed butterfly valve uses a sealing assembly with alternating stacked metal sheets and flexible sealing sheets. This structure effectively compensates for thermal deformation. When the medium is steam or high-temperature flue gas, the temperature fluctuates frequently. The sealing structure deforms automatically to match. It compensates for displacement caused by material thermal expansion, maintains tight sealing contact, and withstands high temperatures. It is suitable for process pipelines with frequent cycling and fluctuating temperatures.

Features of Triple-Eccentric Metal Hard-Sealed Butterfly Valves

The triple-eccentric metal hard-sealed butterfly valve achieves sealing via metal-to-metal contact. Its sealing surface is overlaid with cobalt-based hard alloy. This alloy offers high hardness. It resists erosion from the process medium and tolerates media carrying solid particles. Unlike rubber seals, it will not degrade and fail under high-temperature service. This valve suits harsh media such as high-temperature hot oil and particle-laden flue gas. It complies with API 609 and ISO 15848 standards and achieves strict zero-leakage performance.

Basic Specifications and Installation Advantages

Both valve types can be fitted with worm gear, electric or pneumatic actuators. End connections include wafer, flanged and butt-welded. Valve sizes range from DN50 to DN1200. Pressure ratings cover PN16 up to Class 2500. Compared with gate valves, butterfly valves have a compact outline, low flow resistance and smaller installation footprint. They help end users cut installation and routine maintenance costs.

Project Support and Selection Guidelines

In critical systems such as refining units, power station steam piping and marine fuel oil piping, reliable valve shut-off directly impacts the safety of the whole pipeline. Operators may select suitable valve body, disc and sealing materials according to medium type, temperature and pressure. The manufacturer can supply full sets of material certificates and test reports. These documents satisfy third-party inspection requirements for overseas projects and classification societies.

Summary of Application Scenarios

The two sealing designs fit different application scenarios. The multi-layer sealed version applies to service with recurring temperature variation. The metal hard-sealed version applies to high-temperature media with strong erosion. Sealing lapping processes keep undergoing optimization. These high-performance butterfly valves are an excellent choice for fluid control in high-temperature and high-pressure piping.