
A27H Spring Low Lift Safety Valve
• A27H-10/16Q/16C/25C/40C/64 spring low lift safety valve
• A27Y-25/40P/R series for corrosive media applications
• Threaded connection, DN15–DN80, working temperature ≤200°C
• Discharge coefficient 0.65, opening height ≥1/4 throat diameter
• For steam, water, air, and corrosive media overpressure protection
Gaoshan Valve — A27H Spring Low Lift Safety Valve
Model: A27H-10 / A27H-16Q / A27H-16C / A27H-25C / A27H-40C / A27H-64 / A27Y-25P/R / A27Y-40P/R / A27Y-64P/R | Pressure: PN10 ~ PN64 | Connection: Threaded | Medium: Steam, Water, Air, Corrosive Media
Product Overview
The A27H Spring Low Lift Safety Valve is a compact, threaded-connection pressure relief device designed for steam, water, air, and non-corrosive media systems operating at temperatures up to 200°C. When system pressure exceeds the set value, the spring-loaded valve disc lifts automatically to release excess pressure, protecting equipment and pipelines from damage. The A27Y-P/R series features stainless steel internal components and is specially engineered for corrosive media applications, providing reliable overpressure protection in chemical and aggressive environments.
Key Advantages
Compact Threaded Design
Threaded (screwed) inlet/outlet connection allows for quick and easy installation without flanges, making it ideal for small-diameter pipelines, pressure vessels, and compact equipment where space is limited.
Wide Pressure Range
Available in pressure classes from PN10 to PN64 with set pressure ranges from 0.1 MPa up to the rated pressure, covering a broad spectrum of industrial and commercial applications.
Corrosion-Resistant A27Y Series
The A27Y-P/R variant features stainless steel internal components specifically designed for corrosive media, extending service life in chemical processing, wastewater treatment, and aggressive fluid environments.
Reliable Spring Actuation
Precision-calibrated spring provides consistent set pressure with automatic reseating when pressure returns to normal. The low-lift design ensures rapid response with minimal lift height, reducing wear on seating surfaces.
Multiple Material Options
A27H series offers ductile cast iron (Q), carbon steel (C), and cast steel body options. A27Y-P/R series uses stainless steel construction for maximum corrosion resistance in demanding chemical applications.
High Discharge Efficiency
Certified discharge coefficient of 0.65 ensures effective pressure relief with opening height of at least 1/4 throat diameter, providing adequate flow capacity for overpressure events.
Pressure Test Data
| Parameter | A27H-10 | A27H-16Q/16C | A27H-25C | A27H-40C | A27H-64 |
|---|---|---|---|---|---|
| Set Pressure Range (MPa) | 0.1 ~ 1.0 | 0.1 ~ 1.6 | 0.1 ~ 2.5 | 0.1 ~ 4.0 | 0.1 ~ 6.4 |
| Seal Test Pressure | When Ps < 0.3 MPa: Ps − 0.03 MPa; When Ps ≥ 0.3 MPa: 90% of set pressure | ||||
| Discharge Pressure | ≤ 1.03 × set pressure | ||||
| Reseating Pressure | ≥ 90% of set pressure | ||||
| Opening Height | ≥ 1/4 throat diameter | ||||
| Working Temperature | ≤ 200°C | ||||
| Discharge Coefficient | 0.65 | ||||
| Applicable Medium | Steam, Water, Air | Steam, Water, Air | |||
Materials for Main Parts
| Model | Body, Bonnet | Valve Disc, Seat | Spring | Application |
|---|---|---|---|---|
| A27H-10 | Cast Iron | 2Cr13 | 50CrVA | Steam, Water, Air |
| A27H-16Q | Ductile Cast Iron (QT450) | 2Cr13 | 50CrVA | Steam, Water, Air |
| A27H-16C / 25C / 40C / 64 | WCB Cast Steel | 2Cr13 | 50CrVA | Steam, Water, Air |
| A27Y-25P/R / 40P/R / 64P/R | Stainless Steel | Stainless Steel | 50CrVA | Corrosive Media |
Dimensions & Weight
| DN (mm) | d0 (mm) | R | L (mm) | L1 (mm) | G | ≈H (mm) |
|---|---|---|---|---|---|---|
| 15 | 10 | 1/2″ | 40 | 65 | 1/2″ | 140 |
| 20 | 15 | 3/4″ | 40 | 65 | 3/4″ | 140 |
| 25 | 20 | 1″ | 40 | 76 | 1″ | 155 |
| 32 | 25 | 1 1/4″ | 55 | 85 | 1 1/4″ | 177 |
| 40 | 32 | 1 1/2″ | 62 | 90 | 1 1/2″ | 215 |
| 50 | 40 | 2″ | 67 | 110 | 2″ | 225 |
| 65 | 50 | 2 1/2″ | 76 | 128 | 2 1/2″ | 283 |
| 80 | 65 | 3″ | 110 | 140 | 3″ | 370 |
* R = Inlet thread size; G = Outlet thread size; d0 = Throat diameter; L = Face-to-face length; L1 = Overall length; H = Overall height.
Applicable Media
Water
Air
Non-Corrosive Media
Corrosive Media (A27Y-P/R)

A27H Spring Low Lift Safety Valve — Product Image

A27H Spring Low Lift Safety Valve — Structure Diagram
Request a Quote
Need a reliable threaded safety valve for your steam, water, or air system? Gaoshan Valve offers the A27H series in pressure classes from PN10 to PN64, DN15–DN80, with both standard and corrosion-resistant (A27Y-P/R) configurations. Contact us today for competitive pricing, technical consultation, and fast delivery.