Disclaimer: The key technical specifications in this document are sourced from the official technical documentation for fire protection butterfly valves of Ningjin APC Industries, a top-tier UL/FM-certified fire valve manufacturer in China. This information serves as a production reference for fire valves manufactured at the Ningjin APC Industries facility and for customer product awareness. For any detailed inquiries, please consult our professional team.
1. Introduction & Application Overview
In commercial, industrial, and high-rise building safety, fire protection sprinkler systems, fire inflow water supply networks, and drain piping require flow control valves that guarantee absolute reliability under pressure.Fire protection butterfly valves are engineered specifically to handle continuous high-pressure service while allowing instant status monitoring by Fire Alarm Control Panels (FACP).
This guide outlines the critical technical parameters, material specifications, and model variations for fire sprinkler butterfly valves—helping fire protection contractors, MEP engineers, and industrial valve buyers make fully compliant, zero-leakage procurement decisions.
2. Core Technical Specifications
All standard fire protection butterfly valves in this series are designed, manufactured, and tested to meet stringent international fire safety standards:
- Maximum Working Pressure: 300 PSI (2.1 MPa)
- Maximum Testing Pressure: 600 PSI
- Pressure Compliance Standards: Conforms to UL 1091, ULC/ORD-C1091, and FM 1112
- Working Temperature Range: 0 ~ 80°C (32 ~ 176°F)
- Coating: Epoxy-coated standard (custom coatings available upon request)
- Top Flange Mounting Standard: ISO 5211 compliant
- International Certifications & Listings: UL, CUL, FM, VdS, CE, and CCC
- Potable Water Compliance: Lead-free options certified to NSF/ANSI 61 & NSF/ANSI 372 are available upon request
3. End Connection & Model Breakdown
To accommodate diverse piping configurations—including steel and ductile iron systems—valves are manufactured in Grooved, Wafer, and Grooved/Flanged hybrid end connections.
Grooved End Series (Models: GD-381X, HGD-381X, GD-381G, GD-381L)
Complies with ANSI/AWWA C606 or Metric Standard with a Clear Waterway design. Available in nominal sizes: 2", 2½", 3", 4", 5", 6", 8", 10", and 12".
Wafer End Series (Models: WD-371X, WD-371G, WD-371L)
Compatible with ANSI 125/150 and DIN 2501 PN10/16 flanges. Available in nominal sizes: 2", 2½", 3", 4", 5", 6", 8", 10", and 12".
Grooved / Flanged End Series (Models: HGD-381X-175 / HFGD-381X-175 / HFGD-381X)
Features Grooved End, Grooved × Flanged End, or Flanged × Grooved End combinations. Available in nominal sizes: 2½", 3", 4", 6", 8", and 10".
4. Valve Bill of Materials (BOM)
Every component is chosen to resist internal degradation, maintain bubble-tight shutoff, and prevent stem binding over extended operational cycles.
| No. | Component Description | Material Specification |
|---|---|---|
| 1 | Upper Shaft Sealing Nut | WCB |
| 2 | Shaft Seal | EPDM |
| 3 | Body | Ductile Iron |
| 4 | Upper Shaft | 416 Stainless Steel |
| 5 | Disc + Rubber Seat | Ductile Iron + EPDM Encapsulated |
| 6 | Lower Shaft | 416 Stainless Steel |
| 7 | Lower Shaft Sealing Nut | WCB |
| 8 | End Face Seal (Wafer) / Stem Bushing | EPDM / PTFE or C95400 |
| 9 | O-Ring / Stem Bushing | EPDM / PTFE or C95400 |
| 10 | Gearbox / Lever / Plug | Ductile Iron / Malleable Iron / C95400 |
5. Signal Gearbox & Supervisory Switch Integration
Supervised butterfly valves feature an integrated signal gearbox equipped with internal micro-switches to prevent unauthorized valve closure and trigger alarm signals if tampering occurs.
Gearbox Material Specification
Constructed with Ductile Iron body, cover, worm wheel, and handwheel. Worm and handwheel shafts are engineered from high-strength steel with 416 stainless steel pins. The internal signal switch assembly includes a micro-switch mechanism with nylon clips, EPDM sealing rings, EPDM gaskets, and factory pre-wired leads.
Gear Ratios by Valve Size
| Valve Size Range | Gear Ratio | Handwheel Diameter (ΦD) |
|---|---|---|
| 2" – 6" | 24:1 | 152 mm (2"–5") / 200 mm (6") |
| 8" – 10" | 30:1 | 300 mm |
| 12" | 80:1 | 350 mm |
6. Frequently Asked Questions (FAQ)
Supervised butterfly valves (such as Models GD-381X and WD-371X) include an internal signal switch assembly inside the gearbox. When connected to a fire alarm control panel, any movement away from the fully open position triggers a supervisory signal. Manual lever valves (Models GD-381L / WD-371L) do not incorporate factory-installed supervisory switches.
All valves are rated for a maximum working pressure of 300 PSI and undergo factory hydrostatic testing up to 600 PSI, fully conforming to UL 1091, ULC/ORD-C1091, and FM 1112 standards.
Yes. Valves can be supplied with certified lead-free construction in compliance with NSF/ANSI 61 and NSF/ANSI 372 standards.
7. Procurement & RFQ Checklist
When submitting a Request for Quote (RFQ) for fire protection butterfly valves, ensure your engineering team provides:
- Exact Nominal Size: 2" through 12"
- End Connection: Grooved (ANSI/AWWA C606), Wafer (ANSI 125/150 or DIN PN10/16), or Grooved × Flanged
- Actuation Type: Signal Gearbox (c/w Switch Assembly), Standard Gearbox, or Manual Lever Handle
- Certification Requirements: UL, CUL, FM, VdS, CE, CCC, or NSF/ANSI Lead-Free compliance
