A48Y Spring Full Lift Safety Valve
• A48Y-16C / A48Y-16Q / A48Y-25 spring full lift safety valve
• PN16/PN25, DN32–DN150, working temperature ≤300°C
• WCB cast steel or ductile cast iron body with Stellite seal face
• Full lift design for high-capacity overpressure discharge
• Suitable for boilers, pressure vessels, steam and non-corrosive media
Gaoshan Valve — A48Y Spring Full Lift Safety Valve
Model: A48Y-16C / A48Y-16Q / A48Y-25 | Pressure: PN16 / PN25 | Connection: Flanged | Medium: Steam, Air, Non-Corrosive Media
Product Overview
The A48Y Spring Full Lift Safety Valve is a high-capacity overpressure protection device designed for boilers, pressure vessels, and piping systems handling steam, air, or other non-corrosive media at temperatures up to 300°C. When system internal pressure exceeds the preset allowable limit, the valve automatically opens to its full lift position for maximum discharge capacity. Once pressure drops back to the predetermined safe value, the valve automatically closes to prevent medium leakage, thereby ensuring safe and reliable operation of equipment and pipelines.
Key Advantages
Full Lift Design — Maximum Discharge Capacity
The full lift mechanism opens completely when activated, providing maximum flow area for rapid pressure relief. This is essential for high-energy applications such as steam boilers and large pressure vessels where fast discharge rates are critical for safety.
Stellite Seal Face — Superior Wear Resistance
The disc and seat ring feature Stellite (cobalt-based hard alloy) sealing surfaces that offer exceptional hardness, corrosion resistance, and erosion resistance under repeated cycling conditions, ensuring long-term leak-tight performance.
Automatic Pressure Regulation
Spring-loaded design provides consistent opening pressure without external power sources. The adjustable screw allows precise on-site calibration to match your specific system requirements within a wide range of set pressures.
Premium Internal Components
Disc, seat ring, adjusting ring, valve guide, and stem are all manufactured from 2Cr13 stainless steel, providing excellent corrosion resistance and mechanical strength in demanding steam and hot water environments.
Dual Body Material Options
Available with WCB carbon steel body (A48Y-16C/A48Y-25) for maximum strength and durability, or ductile cast iron body (A48Y-16Q) as a cost-effective option for standard steam and air service conditions.
50CrVA Alloy Spring Steel
High-quality alloy spring maintains stable elastic characteristics through thousands of open-close cycles, ensuring reliable set point accuracy throughout the entire service life without fatigue degradation.
Pressure Test Data & Set Pressure Range
| Nominal Pressure PN | Shell Test (MPa) | Working Pressure Range (MPa) |
|---|---|---|
| PN16 | 2.4 | 0.1 ∼ 0.13 / 0.13 ∼ 0.16 / 0.16 ∼ 0.2 / 0.2 ∼ 0.25 |
| 0.25 ∼ 0.3 / 0.3 ∼ 0.4 / 0.4 ∼ 0.5 / 0.5 ∼ 0.6 | ||
| 0.6 ∼ 0.8 / 0.8 ∼ 1.0 / 1.0 ∼ 1.3 / 1.3 ∼ 1.6 | ||
| Total: 12 pressure stages from 0.1 to 1.6 MPa | ||
| PN25 | 3.8 | 1.6 ∼ 2.0 |
| 2.0 ∼ 2.5 | ||
| Working Temperature: ≤ 300°C | Applicable Medium: Steam, Air, 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 of Valve, Wrench | WCB / Ductile Cast Iron |
| Spring | 50CrVA Alloy Spring Steel |
| Disc, Seat Ring Sealing Face | Stellite (Cobalt-Based Hard Alloy) |
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 | 20 | 115 | 140 | 100 | 78 | 18 | 4-φ18 | 150 | 110 | 88 | 18 | 40 | 4-φ18 | 282 | 100 | 16 |
| 40 | 25 | 120 | 150 | 110 | 88 | 18 | 4-φ18 | 165 | 125 | 102 | 18 | 50 | 4-φ18 | 358 | 110 | 18 |
| 50 | 32 | 135 | 165 | 125 | 102 | 18 20▴ | 4-φ18 | 185 | 145 | 122 | 18 | 65 | 4-φ18 | 365 | 120 | 22 |
| 65 | 40 | 150 | 185 | 145 | 122 | 18 22▴ | 4-φ18 8-φ18▴ | 200 | 160 | 138 | 20 | 80 | 8-φ18 | 366 | 130 | 32 |
| 80 | 50 | 170 | 200 | 160 | 138 | 20 24▴ | 8-φ18 | 220 | 180 | 158 | 20 | 100 | 8-φ18 | 385 | 135 | 42 |
| 100 | 65 | 205 | 220 235▴ | 180 190▴ | 158 162▴ | 20 24▴ | 8-φ22▴ 8-φ18 | 250 | 210 | 188 | 22 | 125 | 8-φ18 | 632 | 180 | 70 |
| 125 | 80 | 210 | 250 270▴ | 210 220▴ | 188 | 22 26▴ | 8-φ18 8-φ26▴ | 285 | 240 | 212 | 22 | 150 | 8-φ22 | 626 | 190 | 87 |
| 150 | 100 | 250 | 285 300▴ | 240 250▴ | 212 218▴ | 22 28▴ | 8-φ22 8-φ26▴ | 340 | 295 | 268 | 24 | 200 | 12-φ22 | 652 | 210 | 92 |
* ▴ = PN25 dimensions (for sizes where PN25 differs from PN16). Z-φd = bolt count and diameter.
Applicable Media
Air
Non-Corrosive Gases
Boiler Systems
Pressure Vessels
A48Y Spring Full Lift Safety Valve — Product Image
A48Y Spring Full Lift Safety Valve — Structure Diagram
Request a Quote
Need an A48Y spring full lift safety valve for your boiler, pressure vessel, or steam system? Gaoshan Valve offers PN16/PN25 ratings, DN32–DN150, WCB cast steel or ductile cast iron body options with Stellite seal faces for superior wear resistance. Contact us today for competitive pricing and technical support.