JIS 20K Metal Hard Sealed Double Flange Butterfly Valve
The JIS 20K metal hard sealed double flange butterfly valve is an industrial isolation and throttling valve engineered for Japanese-standard pipeline systems where flanged end connections, elevated pressure ratings and durable metal-to-metal or resilient seat sealing are required. Manufactured by Trekre Valve at our Wuxi production facility, this double-flanged butterfly valve complies with JIS B2220 flange dimensions and JIS 20K pressure class requirements, making it a practical choice for process plants, power generation auxiliaries, HVAC headers and general industrial services that specify Japanese piping standards alongside ANSI or DIN equipment elsewhere in the same facility.
Unlike compact wafer-type designs, the double flange body provides a stable bolted connection on both upstream and downstream pipe flanges, distributing pipeline loads evenly and simplifying alignment during installation on larger nominal sizes. The valve disc and stem assembly can be configured with a metal hard seat for high-temperature steam and abrasive media, or with an elastomeric resilient seat when bubble-tight shut-off on water, air or low-leakage services is the primary requirement. Body materials include carbon steel WCB and stainless steel CF8/CF8M, with disc and stem metallurgy selected to match corrosion exposure and thermal cycling in the target application.
Construction and sealing design
Connection type: double flange (double-flanged) butterfly valve; flange drilling per JIS B2220 20K; confirm flange facing, drilling, gasket dimensions and the required fasteners for the selected JIS 20K assembly. Do not assume that JIS 10K and 20K joint components are interchangeable.
Structure: double-offset or triple-offset disc geometry available depending on seat type and leakage class target; one-piece stem with blowout-proof lower bearing and adjustable upper gland packing.
Sealing form: metal hard seal (Stellite or stainless steel overlay on disc edge against metal seat ring) for high temperature and erosive duty; resilient PTFE, EPDM or NBR seat options, with suitability for water or air service and shutoff performance to be confirmed for the selected assembly, test medium, pressure direction, differential pressure and agreed acceptance criteria.
Operation: worm gear manual operator as standard configuration; pneumatic double-acting or spring-return actuator and electric multi-turn or quarter-turn actuator available for remote or automated operation.
Body material: carbon steel ASTM A216 WCB, stainless steel CF8 (304) or CF8M (316) castings; ductile iron options for waterworks variants on request.
Disc and stem: stainless steel 304/316 disc with optional Stellite hardfacing; stem in SS416, SS304 or SS316 with surface treatment for wear resistance against metal seats.
Nominal size and pressure rating
Nominal diameter range: DN50 (2 inch) through DN1200 (48 inch) depending on pressure class, seat design and actuator torque envelope. Pressure rating: JIS 20K as primary designation; also available in JIS 10K, ANSI Class 150/300 and EN PN10/PN16/PN25 when project specifications require cross-standard interchangeability. Confirm valve face-to-face dimensions from the approved drawing and the applicable dimensional specification for the selected assembly. JIS B2220 identifies the steel pipe flange requirements, not the complete valve face-to-face dimensions. For steam service above 200 °C, metal-seated configurations with extended gland packing and heat dissipation fins on the bonnet are recommended to protect stem seals from thermal degradation.
The JIS 20K rating indicates suitability for saturated steam, thermal oil, compressed air and general process fluids within the temperature and pressure envelope defined by JIS valve standards and confirmed by hydrostatic and seat closure testing at the factory. When selecting between metal hard seal and resilient seat variants, consider the minimum operating temperature, required leakage class (API 598 or ISO 5208 rate A/B), and whether the valve will operate in modulating throttling positions where cavitation or velocity erosion may occur at partial openings.
Drive methods and actuation
Worm gear manual operation is the conventional drive method for JIS 20K double flange butterfly valves in sizes from DN80 upward, reducing handwheel input torque and providing a self-locking position hold under pipeline differential pressure. The gear unit includes a mechanical position indicator and stop limits at 0° and 90° disc rotation. For frequently cycled or remotely operated lines, pneumatic actuators deliver fast on/off response and are widely used in petrochemical and power plant utility systems. Electric actuators support 4–20 mA modulating control, open/close limit feedback and bus communication for integration with DCS or PLC platforms. Actuator sizing must account for valve break torque at maximum differential pressure, safety factor and local ambient temperature limits.
Applicable working conditions and industries
This JIS 20K metal hard sealed double flange butterfly valve is specified for steam distribution headers, condensate return lines, cooling water circuits, chemical process transfer, pulp and paper white liquor systems, district heating networks and building services where JIS flanged piping is the governing connection standard. Metal hard seated versions handle superheated steam, thermal fluids and abrasive slurries at temperatures typically up to 425 °C depending on body and trim materials. Resilient seated versions serve clean water, chilled water, compressed air and inert gas applications from −10 °C to +120 °C with bubble-tight closure at rated pressure.
Typical industries include thermal power plants, combined heat and power facilities, refineries and chemical complexes with Japanese OEM equipment packages, semiconductor fab utility skids, food and beverage CIP circuits (stainless steel body variants), and municipal energy stations importing JIS-rated valve packages. The double flange format supports removal for maintenance without disturbing the entire pipeline run when adequate flange gap is provided during design. For mixed-standard projects, Trekre can supply companion JIS-to-ANSI adapter spools and confirm face-to-face dimensions against EN 558 Series 13 or ISO 5752 tables to simplify multi-vendor piping coordination on EPC contracts.
When bidirectional flow is required, specify double-offset disc geometry with symmetrical seat loading so the valve maintains rated shut-off performance regardless of flow direction. For unidirectional high-velocity slurry service, a single-offset design with upstream seat orientation may reduce erosion on the trailing seat face during throttling operation.
Product parameters
- Valve type: JIS 20K metal hard sealed double flange butterfly valve
- Model reference: D343H-20K / D343W-20K (project-specific)
- Size range: DN50–DN1200 (2″–48″)
- Pressure rating: JIS 20K / JIS 10K / ANSI 150–300 / PN10–PN25
- Body: WCB carbon steel, CF8/CF8M stainless steel
- Disc: stainless steel with metal seat or PTFE/EPDM resilient seat
- Stem: stainless steel 416/304/316, blowout-proof, adjustable packing
- Operation: worm gear / pneumatic / electric actuator
- Standards: Valve design specification: API 609 / MSS SP-68 as applicable to the ordered configuration; flange dimensions: JIS B2220
- Test standard: API 598, JIS B2003, ISO 5208
- Leakage class: metal seat API 598 permissible rate; resilient seat bubble-tight on water
Selection and installation notes
Confirm JIS 20K flange facing (raised face or flat face), bolt circle, gasket type and pipeline stress loads before ordering. For steam applications, install with the stem horizontal or at a downward inclination to prevent condensate accumulation in the packing chamber. Allow clearance above the worm gear or actuator for maintenance access and handwheel rotation. When mating to non-JIS flanges, provide adapter spools rather than forcing bolt alignment, which can distort the double flange body and compromise seat sealing. Trekre Valve application engineers can review your medium analysis, design temperature and cycle frequency to recommend metal versus resilient seat trim and the appropriate actuator sizing data for your project documentation package.
Quality assurance and delivery
Each JIS 20K double flange butterfly valve undergoes shell hydrostatic test, seat closure test and operational torque verification before shipment from our Wuxi factory. Material certificates for body castings, seat ring hardfacing records and pressure test reports are available for project turnover packages. External surfaces receive primer or epoxy coating for corrosion protection during storage and transit; stainless steel bodies are passivated and protected with removable film. Contact Trekre Valve for dimensional drawings, actuator datasheets and competitive quotations on JIS 20K metal hard sealed double flange butterfly valves for your steam, process or utility pipeline project.
Frequently Asked Questions
What should I confirm when replacing a JIS 20K double-flanged valve?
Send the required size, existing flange details, facing and face-to-face dimensions. Check the selected drawing and operating envelope rather than assuming every JIS 20K valve has the same installation dimensions.
Will my order use a metal seat or the resilient alternative mentioned on the page?
Identify the required sealing construction and request it explicitly on the datasheet and quotation. Provide the medium, operating conditions and shutoff duty so the actual seat and trim can be confirmed.
What operating information is needed before choosing the gearbox or actuator?
State the required duty, available access or utilities, operating frequency and control requirements. Request confirmation of the selected drive and its mounting and operating requirements for the exact valve.