A double offset butterfly valve positions the disc stem off the bore centerline and again off the valve center, so the sealing face lifts away from the seat as soon as the disc begins to open. This near-frictionless rotation removes the continuous rubbing of a centerline disc, lowers operating torque and extends seat life. The sealing is a multi-layer metal hard seat built from stacked stainless lamellae and flexible layers, which withstands high temperature, high pressure and abrasive particles while providing Class IV metal low-leakage shutoff. A streamlined full-bore flow path keeps pressure loss low, and the stem carries anti-blowout and low-emission packing. The valve accepts a smart positioner together with an electric or pneumatic actuator to join a plant DCS, so it handles both throttling control and tight shutoff on demanding process lines.
High-temperature and abrasive service exposes any error in the eccentric disc-and-seat match, so this valve leans on engineering rather than stock. Our valve engineers develop the double-offset geometry and lapping process in-house, grinding the eccentric disc edge and seat cone on CNC equipment to a controlled contact band. Independent development of the offset profile lets the metal seat hold tight shutoff across steam and flue-gas temperature swings, while special alloy bodies such as LCB and duplex steel are cast to order for refinery and power-project conditions.
Specifications
|
Parameter |
Specification |
|
Nominal size |
DN50~DN1600 |
|
Nominal pressure |
PN16~PN100 / Class150~600 |
|
Eccentric design |
Double offset / triple offset |
|
Seat type |
Multi-layer metal hard seat |
|
Body material |
WCB, LCB, 304, 316L, duplex stainless steel |
|
Applicable medium |
High-temperature steam, flue gas, particle-bearing media, high-temp thermal oil |
|
Medium temperature |
-46 C ~ 600 C |
|
Leakage class |
Class IV metal low leakage |
Applications
1.Refinery and petrochemical high-temperature process lines.
The multi-layer metal seat resists hot hydrocarbon vapor and process fluid, and bidirectional shutoff lets the valve block flow from either direction on elevated-temperature piping.
2.Power plant steam and flue-gas ducting.
The offset disc lifts off the seat instead of rubbing, so it tolerates fly-ash abrasion and high steam temperatures without galling the sealing surfaces.
3.Metallurgy and new-energy thermal-oil circuits.
The erosion-resistant metal seat and anti-blowout stem protect the valve on abrasive, high-temperature media where a soft-seat centerline valve would wear out quickly.
Customization
- Double offset or triple offset configuration
- Body material: WCB, LCB, 304, 316L or duplex stainless steel
- Flanged or wafer ends
- Pneumatic or electric actuator with smart positioner for DCS integration
- Special high-temperature alloy bodies produced to customer drawing
- OEM / ODM accepted
Packaging & Transportation
All valves are packed for standard export shipment. Before dispatch every valve undergoes 100% air and water pressure testing; we share pressure-test videos, packing photos and the packing list with the customer, and complete customs documentation is prepared for export orders.
FAQ
Q1. Can you manufacture the valve according to our drawings?
A. Yes, we manufacture to customer drawings. For high-temperature or special-alloy bodies our engineers review the working-condition parameters and issue calculation sheets and sample drawings before production.
Q2. How do you guarantee valve quality?
A. We operate a full ISO9001 system and the plant runs flaw detection, material spectroscopy and water and air pressure test rigs; every valve is pressure tested 100% before delivery.
Q3. What is the delivery time for special high-temperature bodies?
A. Standard stocked bodies ship within about ten days. Special alloy or non-standard castings are produced to order and the lead time is scheduled to match the customer's project milestones.
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