The corrugated insulation cover high temperature wafer butterfly valve is built for hot process lines where standard soft-seated wafer designs cannot maintain seat integrity or protect the actuator from radiant heat. Manufactured by Trekre Valve, this wafer butterfly valve combines a compact between-flange footprint with a corrugated heat shield between the valve body and the worm gear operator, extending service life in petroleum refining, chemical processing, metallurgy, power generation and high-temperature HVAC distribution systems.
Wafer-style installation clamps the valve between two pipeline flanges using through-bolts, reducing overall weight and face-to-face length compared with double-flanged alternatives. The corrugated insulation cover creates an air gap that slows heat transfer toward the stem packing and gearbox, allowing manual worm gear operation on lines carrying steam, hot oil, thermal fluids or exhaust gases at temperatures that would otherwise damage elastomer components on conventional butterfly valves.
High temperature wafer butterfly valve with heat shield
Connection type: wafer (sandwich) between ANSI, DIN, JIS or GB pipeline flanges
Structure: centerline or single-offset disc with multi-layer flexible laminated seal on the disc edge
Heat protection: corrugated stainless steel insulation cover over bonnet and upper stem zone
Size range: 2″ to 80″ (DN50 to DN2000)
Pressure rating: PN10, PN16, PN25, Class 150 and Class 300 (project specific)
Body material: WCB carbon steel, CF8/CF8M stainless steel, WC6/WC9 alloy steel
Disc and seal: stainless steel disc with multi-layer soft folded sealing ring fixed on the plate
Operation: worm gear manual, electric actuator or pneumatic actuator (ISO 5211 top flange)
Temperature range: -29°C to 425°C depending on seal material and line media
Standards: API 609, MSS SP-67, EN 593, GB/T 12238 and project-specific inspection codes
Corrugated insulation cover design and thermal performance
High-temperature pipelines conduct significant heat into valve bonnets and stems. Without thermal isolation, packing materials harden, grease in worm gearboxes evaporates and torque at the handwheel increases until the valve becomes difficult to operate. The corrugated insulation cover on this high temperature wafer butterfly valve functions as a radiant heat barrier and convection break. The folded metal profile increases surface area on the cold side while maintaining a stand-off distance from the hot body, reducing conductive paths to the operator side.
Compared with a standard wafer butterfly valve on the same line, the insulated configuration can reduce heat exposure at the handwheel and gear housing, but does not establish a safe contact temperature for manual operation. This is particularly important on platforms, mezzanines and walk-through pipe racks where personnel may need to close or throttle the valve during upsets under site-specific hot-surface controls and with the protective equipment required by the risk assessment.
The corrugated cover is removable for inspection of stem packing and gland bolts during scheduled shutdowns. Internal insulation blankets or refractory wraps can be added inside the cover for extreme duties above 300°C, subject to engineering review of total envelope height and actuator clearance.
Multi-layer flexible seal on high temperature disc
The disc carries a multi-layer soft folded sealing element bonded and mechanically retained on the valve plate. Each layer contributes to compression set recovery and micro-sealing at the body seat interface. During opening, the seal lifts away with minimal friction because the laminated structure flexes rather than slides heavily across the seat land. Near the closed position, additional stem torque translates into higher seat contact pressure, compensating for thermal expansion differences between disc and body and maintaining bubble-tight shut-off on steam, hot water and thermal oil services within the rated temperature band.
This sealing approach differs from metal hard-seated triple-offset designs intended for highest pressure/temperature combinations with dry gas media. Select the sealing arrangement, required leakage acceptance and operating limits for the actual service; a general comparison with another valve design does not establish the supplied valve’s performance.
Worm gear operation and actuator readiness
Standard supply includes a worm gear operator with self-locking reduction, position indicator and handwheel sized for the calculated stem torque at maximum differential pressure. Gear ratio selection balances stroke time against operator effort so that a single operator can move large bore discs without auxiliary tools. The top flange conforms to ISO 5211, enabling direct mounting of electric or pneumatic actuators when the line is later automated or when remote shutdown is required.
For electric actuation, the corrugated cover protects the actuator adapter and lower actuator housing from continuous heat soak that could degrade internal motor insulation or limit switch components. Pneumatic actuators benefit similarly, especially on hot condensate or steam tracing branches where ambient temperature near the valve exceeds 80°C.
Product parameters summary
Structure: wafer type with corrugated insulation cover on bonnet
Nominal diameter: DN50–DN2000 (2″–80″)
Pressure class: PN10 / PN16 / PN25 / 150LB / 300LB
Body: carbon steel WCB, stainless CF8/CF8M, alloy WC6/WC9
Seal type: multi-layer flexible laminated soft seal on disc
Operation: worm gear manual (standard), electric or pneumatic optional
Design temperature: up to 425°C (material dependent)
End connection: wafer, compatible with raised face flanges per ASME B16.5, EN 1092, JIS B2220
Face-to-face: per API 609 Category A or manufacturer standard table
Testing: shell and seat pressure test per API 598 or EN 12266
Typical applications in hot process industries
Steam distribution headers, condensate return manifolds and boiler blowdown isolation
Hot oil circulation, heat transfer fluid loops and bitumen transfer lines
Refinery process units, catalytic cracker overhead systems and flare knockout drums
Metallurgical furnace cooling water, coke oven gas and sinter plant exhaust ducting
Power plant auxiliary steam, district heating networks and combined heat and power branches
Chemical reactor feed isolation, polymerisation unit vent lines and high-temperature scrubber bypass
Advantages over conventional high temperature butterfly valves
Wafer format reduces pipeline spacing cost and simplifies retrofit between existing flanges without pipe end preparation for double-flange valves.
Corrugated insulation cover lowers operator-side temperature, protecting packing and gearbox lubricant on continuously hot lines.
Multi-layer disc seal delivers friction-free breakaway and strong closing contact pressure for reliable shut-off in thermal cycling service.
Worm gear self-locking drive holds position under flow-induced disc loads without continuous operator input.
ISO 5211 mounting pad supports future upgrade to electric or pneumatic automation without valve body change.
Installation and maintenance guidance
Install the wafer butterfly valve with disc slightly open to protect the laminated seal during flange bolt tightening. Use full-length through-bolts and hardened flat washers per flange standard; do not overtighten one side, which can distort the wafer body. Verify flange gasket selection for temperature and media compatibility. Orient the valve so the corrugated cover does not interfere with adjacent piping, cable trays or actuator access panels.
During commissioning, cycle the valve fully several times at operating temperature to seat the laminated seal evenly. Inspect stem packing for leakage after the first thermal cycle when gland bolts may need minor adjustment. Lubricate worm gear according to the maintenance chart and exercise the valve quarterly on standby hot lines to prevent disc seizure from scale or polymer deposit.
Replace laminated seal components during planned outages when leak rate exceeds process allowance. The wafer design allows removal from one flange side on many installations, reducing downtime compared with spool-piece removal on welded-line double-flange valves.
Selection and ordering information
When requesting a quotation from Trekre Valve, confirm nominal diameter, pressure class, flange standard and drilling table, body material, media composition and maximum/minimum temperature, required operation type (worm gear, electric or pneumatic), insulation cover material preference and any actuator control or feedback accessories. Our engineering team can recommend the optimal corrugated insulation cover high temperature wafer butterfly valve configuration for new construction or replacement of failed soft-seated valves on hot services.
As a professional China valve manufacturer, Trekre maintains production, inspection and spare-part support for high temperature wafer butterfly valves from stock sizes through custom builds. Contact us for dimensional drawings, torque data, thermal performance notes and delivery schedules aligned with your shutdown window.
Quality assurance from factory to site
Each corrugated insulation cover high temperature wafer butterfly valve undergoes material traceability review, dimensional inspection against approved drawings, non-destructive examination of critical welds where applicable and shell and seat pressure testing before release. Factory test reports, material certificates and installation manuals accompany every shipment to support owner inspection and third-party witness requirements on EPC projects.
Our Wuxi assembly centre integrates CNC body machining, seal kit preparation, gearbox pairing and final packaging for domestic and export delivery. Lead times for common carbon steel wafer sizes remain competitive, while alloy bodies and oversized diameters are scheduled with milestone updates for refinery turnaround and power plant outage coordination.
Frequently Asked Questions
Does the corrugated heat shield make the valve safe to touch?
Do not use the shield as a safe-touch guarantee. Have the actual surface temperatures, access protection and site work requirements assessed for the installation; follow the approved operating and maintenance procedure.
What temperature information should I provide for the shielded gearbox arrangement?
Provide the process and ambient conditions, insulation details and operating duty. Request confirmation of the complete valve, stem sealing and gearbox arrangement rather than selecting from the high-temperature product name alone.
How do I check clearance around the shield and handwheel?
Send the available space and intended operator position and request the selected assembly drawing. Include maintenance access and nearby insulation or equipment in the layout review.