JIS20K Three Eccentric Clamp Butterfly Valve Metal Hard Seal

JIS20K Three Eccentric Clamp Butterfly Valve Metal Hard Seal

The JIS20K three eccentric clamp butterfly valve with metal hard seal is a compact wafer-type isolation valve designed for Japanese-standard pipeline systems where space is limited yet elevated pressure ratings and durable shut-off performance are required. Manufactured by Trekre Valve at our Wuxi production facility, this clamp-style butterfly valve conforms to JIS B2220 flange interface dimensions and JIS 20K pressure class requirements, providing a bolted wafer connection between two pipeline flanges without the extended face-to-face length of a full double-flanged body.

Three eccentric disc geometry positions the sealing contact away from the bore centerline, reducing friction during opening and closing while enabling tight metal-to-metal or resilient seat closure at rated pressure. The valve body is available in carbon steel WCB and stainless steel CF8/CF8M castings, with disc and stem metallurgy matched to the service medium, temperature envelope and corrosion exposure of the target application. Operating modes include worm gear manual drive, lever handle, pneumatic actuator and electric quarter-turn actuator, allowing the same valve platform to serve local isolation, remote on/off duty and modulating flow control positions.

Construction and sealing design

Connection type: wafer (clamp) butterfly valve installed between two JIS B2220 flanges using through-bolts or stud sets; suitable for JIS 10K and JIS 20K flange ratings when gasket type, bolt length and face-to-face dimension are confirmed against project piping tables.

Structure: triple-offset disc and stem arrangement; one-piece stem with blowout-proof lower bearing, adjustable upper gland packing and position indicator on the operator.

Sealing form: metal hard seal with Stellite or stainless steel overlay on the disc edge against a metal seat ring for high-temperature steam, thermal oil and erosive media; elastic resilient seat in PTFE, EPDM or NBR for bubble-tight shut-off on water, air and low-leakage services at moderate temperatures.

Operation: worm gear manual operator as standard for sizes DN80 and above; lever handle for smaller nominal diameters; pneumatic double-acting or spring-return actuator and electric multi-turn or quarter-turn actuator for automated lines.

Body material: carbon steel ASTM A216 WCB, stainless steel CF8 (304) or CF8M (316); optional ductile iron variants for waterworks applications on request.

Disc and stem: stainless steel 304/316 disc with optional hardfacing; stem in SS416, SS304 or SS316 with surface treatment for wear resistance against metal seat rings.

Nominal size and pressure rating

Nominal diameter range: 50A through 1200A (DN50–DN1200, approximately 2 inch through 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 cross-standard interchangeability is specified on the data sheet.

Face-to-face length follows JIS B2002 structural length tables for wafer butterfly valves aligned with the nominated flange rating. For saturated steam service above 200 °C, metal-seated configurations with extended gland packing and heat dissipation provisions on the bonnet are recommended to protect stem seals from thermal degradation during cycling operation.

The JIS 20K rating indicates suitability for saturated steam, compressed air, thermal fluids and general process media within the temperature and pressure envelope defined by JIS valve standards and verified by hydrostatic shell test and seat closure test at the factory. When selecting between metal hard seal and elastic resilient seat variants, consider minimum operating temperature, required leakage class per API 598 or ISO 5208, and whether the valve will operate in throttling positions where cavitation or velocity erosion may occur at partial disc openings.

Design and test standards

Design standard: JIS B2064, JIS B2071. Flange standard: JIS B2220. Structural length: JIS B2002. Test and inspection: JIS B2003, supplemented by API 598 and ISO 5208 where project specifications require international acceptance criteria. Trekre Valve can supply material certificates, pressure test reports and dimensional drawings aligned with JIS documentation packages for EPC turnover.

Drive methods and actuation

Worm gear manual operation is the conventional drive method for JIS20K three eccentric clamp butterfly valves in mid-to-large sizes, reducing input torque at the handwheel and providing a self-locking position hold under pipeline differential pressure. The gear unit includes mechanical stop limits at 0° and 90° disc rotation and a position indicator visible from the operating aisle. Lever handle operation suits DN50–DN150 local isolation on clean water and air lines where frequent operation is expected and actuator cost is not justified.

For frequently cycled or remotely operated lines, pneumatic actuators deliver fast on/off response and are widely used in petrochemical utility skids and power plant auxiliary systems. Electric actuators support 4–20 mA modulating control, open/close limit feedback and fieldbus communication for integration with DCS or PLC platforms. Actuator sizing must account for valve break torque at maximum differential pressure, safety factor and ambient temperature limits at the installation location.

Applicable working conditions and industries

This JIS20K three eccentric clamp butterfly valve with metal hard seal is specified for steam distribution branches, condensate return headers, cooling water circuits, chemical process transfer, pulp and paper white liquor systems, district heating networks and building services where JIS-rated wafer 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 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 in stainless steel body variants, and municipal energy stations importing JIS-rated valve packages. The wafer clamp format minimizes overall envelope length compared with double-flanged designs, making it suitable for tight mechanical rooms, skid-mounted packages and retrofit installations where existing flange spacing cannot accommodate longer valve bodies.

When bidirectional flow is required, specify symmetrical triple-offset seat loading so the valve maintains rated shut-off performance regardless of flow direction. For unidirectional high-velocity slurry service, confirm upstream seat orientation with the application engineer to reduce erosion on the trailing seat face during throttling operation.

Product parameters

• Valve type: JIS20K three eccentric clamp (wafer) butterfly valve, metal hard seal
• Model reference: D373H-20K / D373W-20K (project-specific)
• Size range: 50A–1200A (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 / lever handle / pneumatic / electric actuator
• Design standard: JIS B2064, JIS B2071, JIS B2220, JIS B2002
• Test standard: JIS B2003, API 598, ISO 5208
• Leakage class: metal seat per API 598; 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. Wafer valves rely on the pipeline flanges for structural support; do not use wafer bodies as pipe anchors or expansion joint substitutes. For steam applications, install with the stem horizontal or at a slight 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 or confirm bolt circle compatibility rather than forcing bolt alignment, which can distort the wafer body and compromise seat sealing. Trekre Valve application engineers can review 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 JIS20K three eccentric clamp 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 quotations on JIS20K metal hard sealed clamp butterfly valves for your steam, process or utility pipeline project.