General HVAC valves look simple until the wrong body material, connection, sealing system or operating function is installed in the wrong part of the water circuit.
Select across YONGFAN ISO 228 brass threaded valves (Q11F, Z15W, J11F, H12X/H14W, SY11, B725X, Y13X), 304/316 stainless threaded valves, flanged/wafer/lug butterfly valves (D71X, D371X, D341X, SD341X, D373H to DN2000), and resilient-seated ductile iron gate valves (Z45X, Z41X, SZ45X).
Installing a globe stop valve on FCU lines where fast quarter-turn ball isolation is required adds unnecessary head loss and slower operation.
Specifying manual gate valves instead of automatic check valves on pump discharge headers leaves the system exposed to reverse flow upon pump trip.
Leaving strainers off upstream of control valves and PRVs allows welding slag, pipe scale, and debris to foul precision seats.
Using wafer-style butterfly valves where downstream pipework must be dismantled for maintenance prevents dead-end isolation.
Nine standard SKUs for building HVAC and plumbing circuits (ISO 228, PN 1.6 MPa, -20 °C to 120 °C, brass body). Includes Q11F-16T quarter-turn ball valves, Z15W-16T full-bore gate valves, J11F-16T manual throttling stop valves, H12X-16T vertical & H14W-16T horizontal check valves, SY11-16T strainers, combined Y-strainer ball valves, B725X-16T automatic float air vents, and Y13X-16T diaphragm PRVs.
Material upgrade range for aggressive water, mild acids, oil, and clean utilities (PN 1.6 MPa, -20 °C to 110 °C, BSPT/BSP/NPT/DIN 2999). Includes 1-piece, 2-piece, and 3-piece Q11F-16P ball valves (with PTFE seats and blowout-proof stems), Z11W-16P gate valves, J11W-16P stop valves, H12W/H14W check valves, and GL11F-16P Y-strainers.
Compact butterfly valves for large-pipe isolation (DN50–DN500, soft-seal rated <=80 °C). D71X features a slim wafer body clamped between flanges with manual lever operation. D371X features a lugged body with individual threaded holes and worm-gear operator, suitable for dead-end service when downstream piping is disconnected.
Heavy-duty flanged butterfly valves for central plant mains (DN50–DN2000). SD341X (DN50–DN1000) integrates axial telescopic compensation into the flanged valve assembly, absorbing thermal expansion and simplifying pump/valve replacement without extra dismantling joints.
Triple-eccentric metal hard-sealed butterfly valve engineered for high-temperature, high-pressure, and abrasive media (DN50–DN2000, PN 0.6–4.0 MPa, 80 °C to 550 °C). Delivers bi-directional tight shut-off on steam, thermal oil, hot gases, and high-temperature hydronic circuits.
Full-bore waterworks-style isolation valves (DN40–DN1000) with ductile-iron body, fully rubber-encapsulated wedge (EPDM/NBR), stainless-steel stem, and fusion-bonded epoxy coating. Z45X features non-rising stem for tight headroom; Z41X features rising stem for visual position; SZ45X (DN50–DN600) is engineered for underground buried service.
| Valve Family | Primary Duty | Published Boundary | First Selection Input |
|---|---|---|---|
| Brass Threaded Valves | Small-DN isolation, check, straining, venting and local pressure reduction | ISO 228, PN1.6 MPa, -20 to 120 °C | Required pipe function & size |
| 304 / 316 Stainless Threaded | Similar line duties where brass is chemically unsuitable | PN1.6 MPa, -20 to 110 °C, BSPT/BSP/NPT | Fluid chemistry & purity requirement |
| D71X Wafer Butterfly | Compact wafer isolation clamped between flanges | DN50–DN500, soft seal ≤80 °C | Wafer connection acceptable? |
| D371X Lug Butterfly | Lug / end-of-line-style serviceable isolation | DN50–DN500, soft seal ≤80 °C | Need independent lugged connection? |
| D341X Flanged Butterfly | Large flanged water/process distribution isolation | Typical DN50–DN2000 mains | Flange standard & actuator torque |
| SD341X Telescopic Butterfly | Flanged isolation + telescopic axial compensation | Typical DN50–DN1000 | Required axial compensation length |
| D373H Metal Hard-Sealed | High-temperature triple-eccentric hard-sealed duty | DN50–DN2000, PN0.6–4.0 MPa, 80–550 °C | Operating temp, pressure & medium |
| Z45X / Z41X / SZ45X Gate | Large water-main resilient-seated gate isolation | Typical DN40–DN1000 depending variant | Above-ground, visible stem, or buried |
Define isolation (ball/gate/butterfly), throttling (stop), backflow (check), straining, or venting.
Nominal size (DN15–DN2000), thread standard (ISO 228 / NPT), or flange standard (GB/DIN/ANSI).
Working pressure (PN10/16/25/40) and fluid temperature range (-20 °C to 550 °C).
Brass, 304/316 stainless, ductile iron; manual lever, gear, electric or pneumatic actuator.
YONGFAN application engineers will verify metallurgy compatibility, confirm flange bolt circles, calculate actuator torque requirements, and supply submittal drawings.
Every valve body is hydrostatically tested to 1.5× nominal pressure per API 598, EN 12266-1, and GB/T 13927.
Resilient EPDM/NBR and metal seats undergo bidirectional tight shut-off testing to verify leakage class.
Gearbox and bare-shaft butterfly valves are verified for seating torque to ensure reliable manual or motorized actuation.
Cast bodies and forged brass parts are lot-coded for complete chemical composition and metallurgical traceability.
| Size Band & Models | Construction Type | Documented Lead Time | Commercial Terms |
|---|---|---|---|
| DN50 – DN300 D71X / D371X / D341X | Wafer / Lug / Flanged Soft Seal | 10 – 20 Working Days | EXW, FOB, CIF, DDP |
| DN350 – DN800 D341X / SD341X | Large Flanged & Telescopic | 25 – 40 Working Days | EXW, FOB, CIF, DDP |
| DN800+ and D373H Metal Seal | Heavy Mains & Hard-Sealed 550 °C | 40 – 60 Working Days | EXW, FOB, CIF, DDP |
For small threaded water branches, the Q11F-16T brass ball valve is the most direct documented option when fast quarter-turn isolation is required.
Use a gate valve where full-bore isolation and minimal obstruction in the fully open position are priorities, and slower handwheel operation is acceptable. Review Z15W-16T for small lines or resilient gate valves for large mains.
The J11F-16T brass stop valve and J11W-16P stainless stop valve provide disc-and-seat manual throttling. For calibrated hydronic balance, use a dedicated balancing valve instead.
Use the check-valve family. YONGFAN documents H12X/H12W vertical spring-loaded and H14W horizontal swing check-valve configurations across brass and stainless ranges.
Choose stainless when fluid chemistry, chloride exposure, deionized water purity, or project material specifications rule out brass. 304 and 316 options are available.
A wafer valve (D71X) is clamped between two flanges. A lug valve (D371X) has threaded bolt lugs around the body and holds dead-end isolation when downstream piping is dismantled.
Standard soft-seated butterfly valves operate up to ≤80 °C. The D373H triple-eccentric metal hard-sealed butterfly valve operates from 80 °C to 550 °C for steam and high-temp hot water.
The published typical size range extends to DN2000 for D341X flanged and D373H hard-sealed butterfly valves.
Yes. The supplier source documents electric and pneumatic actuator options for D341X, SD341X, D373H, and relevant D371X configurations with standard ISO 5211 mounting tops.
No. General valves perform isolation, check, straining, venting or basic pressure reduction. Modulating control valves, balancing valves and 100X–900X hydraulic valves have separate sizing requirements.
A manual ball or stop valve cannot replace a modulating control valve or dynamic balancing valve simply because both can adjust flow.
Do not apply D71X or D371X soft-seated butterfly valves above 80 °C; specify D373H triple-eccentric metal hard-sealed valves for high-temperature service.
Threaded brass Y13X diaphragm PRVs are for small terminal lines; do not substitute them for large pilot-operated 200X hydraulic PRVs on main headers.
Do not claim potable water (WRAS/NSF) or fire-safe (API 607/CCCF) certification unless verified for the specific SKU and market.
Send your pipeline diameters, fluid temperature, working pressure, connection type, and required operating duty. YONGFAN engineers will confirm valve metallurgy, supply flange drillings, and provide certified submittal drawings.
