A41H Seal Type Spring Low Lift Safety Valve
• A41H-16C / A41H-16Q / A41H-25 seal type spring low lift safety valve
• PN16/PN25, DN40–DN100, working temperature ≤300°C
• Enclosed (sealed) bonnet design — discharge can be piped to safe location
• WCB cast steel or ductile cast iron body options
• Suitable for water, air, oil products, and non-corrosive media
Gaoshan Valve — A41H Seal Type Spring Low Lift Safety Valve
Model: A41H-16C / A41H-16Q / A41H-25 | Pressure: PN16 / PN25 | Connection: Flanged | Medium: Water, Air, Oil Products
Product Overview
The A41H Seal Type Spring Low Lift Safety Valve is an enclosed overpressure protection device designed for equipment and piping systems handling water, air, oil products, and other non-corrosive media at temperatures up to 300°C. Unlike open-bonnet safety valves that vent directly to atmosphere, this model features a sealed (enclosed) bonnet construction where the discharge can be safely piped to a collection system or remote location. When system internal pressure exceeds the preset allowable value, the valve automatically opens for full discharge. Once pressure returns to the predetermined safe level, the valve closes automatically to ensure continuous safe operation.
Key Advantages
Sealed (Enclosed) Bonnet Design
Unlike conventional open-type safety valves that release directly into the surrounding area, the A41H features a fully enclosed bonnet that allows the discharge medium to be routed through a pipe to a safe collection point or recovery system — ideal for hazardous or valuable fluids.
Automatic Overpressure Response
Spring-loaded mechanism ensures immediate opening when internal pressure exceeds the set point, discharging excess medium through the enclosed outlet path. The valve automatically reseats when pressure drops back below the predetermined threshold.
Premium Internal Components
Critical moving parts including disc, seat ring, adjusting ring, valve guide, adjusting screw, and stem are all manufactured from 2Cr13 stainless steel, offering excellent corrosion resistance and mechanical durability under repeated cycling.
Dual Material Body Options
Available with WCB carbon steel body (A41H-16C/A41H-25) for high-strength applications, or ductile cast iron body (A41H-16Q) as a cost-effective alternative for standard water, air, and oil service conditions.
50CrVA Alloy Spring Steel
High-performance alloy spring steel provides stable elastic characteristics through thousands of operation cycles, maintaining consistent set-point accuracy without fatigue degradation throughout its service life.
Wide Media Compatibility
Designed for water, air, oil products, and general non-corrosive industrial media. The enclosed design makes it particularly suitable for applications where direct atmospheric venting is not permitted due to environmental or process requirements.
Pressure Test Data & Set Pressure Range
| Nominal Pressure PN | Shell Test (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 | ||
| Total: 8 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: Water, Air, Oil Products, 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, Adjusting Screw, Stem | 2Cr13 Stainless Steel |
| Bonnet, Cap of Valve, 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) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 40 | 32 | 120 | 150 | 110 | 88 | 18 | 4-φ18 | 150 | 110 | 88 | 18 | 40 | 4-φ18 | 300 | 110 | 16 |
| 50 | 40 | 135 | 165 | 125 | 102 | 18 20▴ | 4-φ18 | 165 | 125 | 102 | 18 | 50 | 4-φ18 | 315 | 115 | 18 |
| 65 | 50 | 140 | 185 | 145 | 122 | 18 22▴ | 4-φ18 8-φ18▴ | 185 | 145 | 122 | 18 | 65 | 4-φ18 | 350 | 125 | 24 |
| 80 | 65 | 170 | 200 | 160 | 138 | 20 24▴ | 8-φ18 | 200 | 160 | 138 | 20 | 80 | 8-φ18 | 350 | 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 | 57 |
* ▴ = PN25 dimensions (for sizes where PN25 differs from PN16). Z-φd = bolt count and diameter.
Applicable Media
Air
Oil Products
Non-Corrosive Gases
Process Piping
A41H Seal Type Safety Valve — Product Image
A41H Seal Type Safety Valve — Structure Diagram
Request a Quote
Need an A41H sealed safety valve for your water, air, oil, or non-corrosive piping system? Gaoshan Valve offers PN16/PN25 ratings, DN40–DN100, WCB cast steel or ductile cast iron body options with enclosed bonnet design. Contact us today for competitive pricing and technical support.