Multi-level butterfly valve

It is a high-performance butterfly valve with a composite sealing structure. It achieves a higher level of sealing and pressure resistance through a multi-layer metal or soft and rigid combined sealing structure. It combines the portability of a traditional butterfly valve with the sealing characteristics of a ball valve, and is widely used in high-temperature, high-pressure, and corrosive environments in petroleum, chemical, electric power, metallurgy, and other industries.

+86 18858752875 gd@gaodun-valve.com

Online Inquiry Contacts

Product Details

1. Basic Structure of Multi-Layer Choke
(1) Valve Body
● Material: Cast Steel (WCB), Stainless Steel (CF8/CF8M), Alloy Steel (WC6/WC9)

● Connection method: plate, flange, butt welding.

(2) Throttle Disc
● Multi-layer sealing structure: Usually composed of a metal sealing ring of a soft sealing layer (graphite/PTFE) to improve sealing performance.

Eccentric Design:

● Double eccentricity (valve stem deviates from the center of the throttle disc) → Reduces friction and prolongs service life.

● Triple eccentricity (valve stem and sealing surface are eccentric) → Suitable for high temperature and high pressure (such as steam pipelines).

(3) Valve stem
● Material: Stainless steel (SS316), alloy steel (17-4PH).

● Structure: Integrated forging to avoid the risk of breakage.

(4) Sealing system
● Metal solid seal: suitable for high temperature (≤600°C) and high pressure (PN100 and above).

● Soft seal metal composite: Takes into account both elastic seal and pressure resistance (such as PTFE stainless steel).

● Flame Retardant Design: Some models use graphite seals, which can remain sealed during a fire (API 607 certification).

2. Working principle of multilayer choke
● Open state: The throttle plate rotates parallel to the flow channel, and the resistance to the flow of the medium is extremely small.

● Closed state: The butterfly plate rotates 90° and the multi-layer sealing surface fits snugly to achieve bi-directional sealing (can withstand positive/back pressure).

● Flow control: control the flow by partial opening (such as 30°~70°), but the control accuracy is lower than that of the special control valve.

3. Main Features of Multilayer Butterfly Valve
✅ Benefits
● High sealing: The leakage rate can reach the ANSIVI (Zero Leakage) level, which is better than ordinary butterfly valves.

● High pressure and high temperature resistance: The tri-eccentric design can withstand PN100 and high temperature 600°C (such as steam, oil and gas pipelines).

● Long Service Life: The metal seal is wear-resistant and suitable for frequent switching.

● Bi-directional seal: Both positive and negative pressure can be effectively sealed.

● Light Weight: Compared to gate valves or ball valves of the same pressure level, it is lighter and smaller in size.