JIS 10K Worm Gear Wafer Butterfly Valve Triple Offset Metal Hard Seal
The JIS 10K worm gear wafer butterfly valve is a compact isolation and throttling valve designed for Japanese-standard pipeline systems where space is limited yet reliable metal hard sealing and elevated pressure capability are required. Manufactured by Trekre Valve at our Wuxi production facility, this wafer-type butterfly valve conforms to JIS B2220 flange dimensions at the 10K pressure class and incorporates a triple-offset disc geometry with metal hard seat sealing for dependable performance in process water, steam distribution, HVAC headers and general industrial utility lines.
Compared with double-flanged alternatives, the wafer body installs between two pipeline flanges using through-bolts and requires minimal face-to-face length, making it well suited for retrofit projects, equipment skids and high-rise building services where pipe rack clearance is constrained. The worm gear manual operator reduces input torque on larger nominal sizes and provides a self-locking position hold under differential pressure, while the triple-offset disc path keeps the sealing surfaces separated during opening and closing strokes to minimize wear and extend service life.
Construction and sealing design
Connection type: wafer (double-clamp) butterfly valve; installs between JIS B2220 10K flanges with through-bolts and gaskets; confirm the selected pressure designation, flange drilling, bolt-hole dimensions, fastener size and length, gaskets and face-to-face dimensions against the approved drawing. Face-to-face dimensions alone do not establish compatibility between JIS 10K and JIS 20K flange assemblies.
Structure: triple-offset (triple eccentric) disc geometry; one-piece stem with blowout-proof lower bearing and adjustable upper gland packing; disc rotation 90° for full open or closed position.
Sealing form: metal hard seal with Stellite or stainless steel overlay on the disc edge against a metal seat ring; optional resilient PTFE, EPDM or NBR seat configuration available for bubble-tight water and air service at moderate temperatures when project specifications require zero-leakage closure.
Operation: worm gear manual operator as standard; pneumatic double-acting or spring-return actuator and electric multi-turn or quarter-turn actuator available for remote or automated operation on request.
Body material: carbon steel ASTM A216 WCB, stainless steel CF8 (304) or CF8M (316) castings; ductile iron options for waterworks variants when corrosion exposure is low.
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 DN600 (24 inch) depending on pressure class, seat design and actuator torque envelope. Pressure rating: JIS 10K as primary designation; also available in JIS 20K, ANSI Class 150/300 and EN PN10/PN16 when project specifications require cross-standard interchangeability. Face-to-face length follows manufacturer standard tables aligned with JIS wafer butterfly valve dimensions and confirmed against EN 558 Series 20 or ISO 5752 short-pattern tables for mixed-standard EPC projects.
For steam service above 200 °C, metal-seated configurations with extended gland packing and heat dissipation provisions on the stem seal area are recommended to protect packing materials from thermal degradation. The JIS 10K 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. Triple-offset geometry is particularly advantageous for metal-seated applications because the disc lifts off the seat immediately at the start of the stroke, reducing friction and galling on high-cycle lines.
Drive methods and actuation
Worm gear manual operation is the conventional drive method for JIS 10K wafer butterfly valves in sizes from DN80 upward, reducing handwheel input torque and providing a positive position hold under pipeline differential pressure. The gear unit includes a mechanical position indicator and adjustable 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. The worm gear housing is typically cast iron or aluminum with grease-lubricated worm and wheel gears; gear ratio is selected to keep handwheel rim force within ergonomic limits for the nominated valve size and pressure class. For underground or padlocked installations, an optional lockable gear cover or key-operated handwheel lock can be supplied to deter unauthorized operation on municipal water networks.
Applicable working conditions and industries
This JIS 10K worm gear wafer butterfly valve is specified for cooling water circuits, condensate return lines, chemical process transfer, pulp and paper white liquor systems, district heating branch connections, building services and environmental water treatment plants where JIS-rated wafer valves are 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 compact wafer format supports installation in tight pipe racks without the extended body length of double-flanged designs, while still allowing removal for maintenance when adequate flange gap is provided during piping design.
For mixed-standard projects, Trekre can supply companion JIS-to-ANSI adapter spools and confirm face-to-face dimensions against EN 558 Series 20 tables to simplify multi-vendor piping coordination on EPC contracts. When bidirectional flow is required, specify triple-offset disc geometry with symmetrical seat loading so the valve maintains rated shut-off performance regardless of flow direction.
Product parameters
- Valve type: JIS 10K worm gear wafer butterfly valve, triple offset metal hard seal
- Model reference: D373H-10K / D373W-10K (project-specific)
- Size range: DN50–DN600 (2″–24″)
- Pressure rating: JIS 10K / JIS 20K / ANSI 150–300 / PN10–PN16
- 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
- Design standard: API 609, MSS SP-68. Flange connection reference: JIS B2220; confirm applicability for the selected configuration
- 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 10K 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 wafer 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. Each JIS 10K wafer 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.
Frequently Asked Questions
Can I use this JIS 10K wafer valve with a different flange class?
Do not assume compatibility from a general series description. Provide the actual mating flange dimensions, facing and piping specification and request confirmation for the exact selected valve and fasteners.
What clearance should I check for the wafer disc and gearbox?
Send the pipe bore, flange details and nearby obstructions. Request the selected assembly drawing so disc travel, face-to-face fit and handwheel access can be checked together.
Does the triple-offset metal-seat description guarantee a particular leakage result?
Specify the required shutoff acceptance and test conditions and request confirmation for the ordered configuration. The geometry and seat description do not replace the agreed leakage test requirements.