When you spec a flange butterfly valve, you’re really balancing a triangle: sealing reliability, footprint, and lifecycle cost. Over the past year, I’ve toured a few northern China shops and—full disclosure—ended up rather impressed by the D341J-16 rubber-lined series coming out of Xushui District, Baoding. It’s not flashy; it just works.

Origin: North Guzhuangying Village, Ansu Town, Xushui District, Baoding City, Hebei, China. If you’ve followed China’s valve corridor, you know the supply chain here is tight—rubber lining, machining, epoxy, and testing in close proximity. That keeps lead times sane and prices, well, competitive.
| Size (DN) | DN50–DN1000 | Pressure rating | PN10/PN16 (1.0–1.6 MPa) |
| Medium | Water, oil, gas | Temperature | -10 to 80 ℃ |
| Body materials | Ductile iron, carbon steel, stainless steel | Connection | Flange |
| Seat/Lining | Rubber-lined (EPDM/NBR options, project-dependent) | Service life | ≈50,000–100,000 cycles (real-world use may vary) |


Municipal water, HVAC loops, light-industrial process water, irrigation, and low-temperature oil/gas lines. In a food plant case I followed, a DN400 flange butterfly valve with EPDM seat replaced an aging gate valve, cut maintenance by half, and—surprisingly—reduced actuator load due to lower torque.
“No visible seat set after 20k cycles,” one facility engineer told me. Another liked the straightforward flange alignment and the clean bore. There was a minor gripe about paint scuffs in transit (packaging has since been bumped up, they say).

| Vendor | Size range | Seat options | Certs | Lead time | Notes |
|---|---|---|---|---|---|
| HBYS (Baoding) | DN50–DN1000 | EPDM, NBR | ISO 9001, CE | 2–5 weeks (≈) | Good value, strong rubber bond |
| Brand X (imported) | DN50–DN1200 | EPDM, NBR, FKM | CE, WRAS, ISO 9001 | 6–10 weeks (≈) | Premium pricing, broader approvals |
| Regional Supplier | DN80–DN600 | EPDM | ISO 9001 | Stock for DN≤300 | Fast swaps, limited specials |

Bottom line? For utilities and light process duty, a rubber-lined flange butterfly valve like the D341J-16 hits that sweet spot of price-to-performance—and, actually, installation is pleasantly uneventful.