
A47H Spring Low Lift Safety Valve
• A47H-16C / A47H-16Q / A47H-25 spring low lift safety valve
• PN16/PN25, DN32–DN150, working temperature ≤300°C
• WCB cast steel or ductile cast iron body options
• Automatic overpressure protection with spring-loaded mechanism
• Suitable for steam, water, and non-corrosive piping systems
Gaoshan Valve — A47H Spring Low Lift Safety Valve
Model: A47H-16C / A47H-16Q / A47H-25 | Pressure: PN16 / PN25 | Connection: Flanged | Medium: Steam, Water, Non-Corrosive Media
Product Overview
The A47H Spring Low Lift Safety Valve is a specialized overpressure protection device designed for steam, water, and non-corrosive media in industrial equipment and pipeline systems operating at temperatures up to 300°C. When system pressure exceeds the preset allowable limit, the valve automatically opens to discharge excess fluid, thereby protecting downstream equipment from damage. Once pressure returns to the predetermined safe value, the valve automatically closes to ensure continuous and reliable operation of the entire piping network.
Key Advantages
Automatic Overpressure Protection
Spring-loaded mechanism ensures immediate response when system pressure exceeds the set value. Automatically opens to discharge excess medium and closes when pressure drops back to normal, providing fail-safe protection without manual intervention.
Precision Spring Design
Equipped with high-quality 50CrVA alloy spring steel that maintains consistent elastic performance under repeated loading cycles. The low-lift design provides accurate set pressure control within tight tolerance bands.
Durable Sealing Components
Key internal components including disc, seat ring, adjusting ring, valve guide, and stem are manufactured from 2Cr13 stainless steel, offering excellent corrosion resistance and wear resistance for extended service life in demanding environments.
Dual Material Options
Available with WCB carbon steel body (A47H-16C/A47H-25) for higher strength applications, or ductile cast iron body (A47H-16Q) as a cost-effective alternative for lower-pressure steam and water service conditions.
Wide Pressure Setting Range
PN16 models cover eight working pressure stages from 0.1 to 1.6 MPa, while PN25 models cover two stages from 1.6 to 2.5 MPa. The adjustable screw allows precise calibration to match your specific system requirements on site.
Compact Vertical Installation
Vertical flanged connection design simplifies installation on boilers, vessels, and headers. Standard face-to-face dimensions ensure compatibility with common industrial mounting arrangements and easy maintenance access.
Pressure Test Data & Set Pressure Range
| Nominal Pressure PN | Shell Test Pressure (MPa) | Working Pressure Range (MPa) |
|---|---|---|
| PN16 | 2.4 | 0.1 ∼ 0.14 |
| 0.14 ∼ 0.2 / 0.2 ∼ 0.3 / 0.3 ∼ 0.45 | ||
| 0.45 ∼ 0.65 / 0.65 ∼ 0.9 | ||
| 0.9 ∼ 1.2 / 1.2 ∼ 1.6 | ||
| PN25 | 3.8 | 1.6 ∼ 2.0 |
| 2.0 ∼ 2.5 | ||
| Working Temperature: ≤ 300°C | Applicable Medium: Steam, Water, Non-Corrosive Media | ||
Materials for Main Parts
| Part Name | Material |
|---|---|
| Body | WCB Carbon Steel / QT450-10 Ductile Cast Iron |
| Disc, Seat Ring, Adjusting Ring, Valve Guide, Stem | 2Cr13 Stainless Steel |
| Bonnet Cap, Wrench | WCB / Ductile Cast Iron |
| Spring | 50CrVA Alloy Spring Steel |
Dimensions & Weight
| DN (mm) | d0 (mm) | L (mm) | D (mm) | K (mm) | g (mm) | b (mm) | Z-φd | D1 (mm) | K1 (mm) | g1 (mm) | b1 (mm) | D1′ (mm) | Z’-φd’ | H (mm) | H1 (mm) | Weight (kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 32 | 25 | 115 | 140 | 100 | 78 | 18 | 4-φ18 | 135 | 100 | 78 | 18 | 32 | 4-φ18 | 282 | 100 | 14 |
| 40 | 32 | 120 | 150 | 110 | 88 | 18 | 4-φ18 | 150 | 110 | 88 | 18 | 40 | 4-φ18 | 355 | 110 | 16 |
| 50 | 40 | 135 | 165 | 125 | 102 | 18 20▴ | 4-φ18 | 165 | 125 | 102 | 18 | 50 | 4-φ18 | 360 | 120 | 18 |
| 65 | 50 | 140 | 185 | 145 | 122 | 18 22▴ | 4-φ18 8-φ18▴ | 185 | 145 | 122 | 18 | 65 | 4-φ18 | 370 | 125 | 24 |
| 80 | 65 | 170 | 200 | 160 | 138 | 20 24▴ | 8-φ18 | 200 | 160 | 138 | 20 | 80 | 8-φ18 | 385 | 135 | 38 |
| 100 | 80 | 170 | 220 235▴ | 180 190▴ | 158 162▴ | 20 24▴ | 8-φ18 8-φ22▴ | 220 | 180 | 158 | 20 | 100 | 8-φ18 | 580 | 160 | 58 |
| 150 | 125 | 220 | 285 300▴ | 240 250▴ | 212 218▴ | 22 28▴ | 8-φ22 8-φ26▴ | 265 | 240 | 212 | 22 | 150 | 8-φ22 | 633 | 210 | 88 |
* ▴ = PN25 dimensions (for sizes where PN25 differs from PN16). Z-φd = bolt count and diameter.
Applicable Media
Water
Non-Corrosive Gases
Boiler Systems
Pressure Vessels
A47H Spring Low Lift Safety Valve — Product Image

A47H Spring Low Lift Safety Valve — Structure Diagram
Request a Quote
Need an A47H spring low lift safety valve for your boiler, vessel, or steam piping system? Gaoshan Valve offers PN16/PN25 ratings, DN32–DN150, with WCB cast steel or ductile cast iron body options. Contact us today for competitive pricing, technical consultation, and fast delivery.