The A28H/Y Type Safety Valve is aspring-loaded full-lift safety valvedesigned for reliable overpressure protection in medium-pressure industrial systems. Compared with micro-lift valves such as A21 or A27 series, the A28H/Y adopts afull-opening (full-lift) structure, allowing rapid discharge of large volumes of media once the set pressure is exceeded. This makes it particularly suitable for equipment whereinstant pressure relief is critical.
The A28 series is typically divided into:
A28H: Suitable fornon-corrosive mediasuch as air, steam, water, and mixed gases
A28Y: Designed forcorrosive media, using upgraded materials and sealing structures
These valves are widely applied in systems withworking temperatures ≤200°C, and are commonly installed on pressure vessels, pipelines, and industrial equipment as a primary safety protection device.
Typical technical ranges include:
Nominal diameter:DN15–DN80
Pressure range:PN1.6–PN10.0 MPa
Applicable media:Air, steam, water, nitrogen-hydrogen mixtures, and industrial gases
With strong production capabilities and mature engineering experience, China has become a leading global supplier of A28H/Y safety valves, providing both standard and customized solutions.
The A28H/Y safety valve operates on adirect spring-loaded mechanism combined with a full-lift action. Under normal conditions, the spring force keeps the valve disc tightly sealed against the seat. When system pressure exceeds the preset value:
The spring force is overcome
The valve disc lifts rapidly to a full-open position
A large volume of medium is discharged instantly
The valve reseats when pressure returns to safe limits
Thisfull-lift discharge characteristicensures fast response and effective pressure relief, making it ideal for systems where pressure can rise rapidly.
Full-Lift Design
Enables rapid and high-capacity discharge, ensuring maximum safety in emergency conditions.
Closed Bonnet Structure with Lever (Optional)
Prevents medium leakage and allows manual testing of valve operation when equipped with a lifting lever
Spring-Loaded Mechanism
Provides precise pressure control and reliable repeatability.
Threaded or Flanged Connection
Offers flexibility for different installation requirements.
Advanced Sealing Technology
H type: Hard sealing with alloy surfacing (e.g., D507)
Y type: Cobalt-based hard alloy sealing for corrosive media
Wide Material Options
Including cast steel, forged steel, and stainless steel for different industrial environments
These structural advantages ensure that the A28H/Y valve delivershigh discharge efficiency, strong sealing performance, and long service life.
Chinese manufacturers utilize advanced production technologies and strict quality control systems to ensure the reliability of A28H/Y safety valves.
The valve body and key components are selected based on working conditions:
Carbon steel (WCB / HT200)for general industrial applications
Stainless steel (304, 316, CF8M)for corrosive environments
Alloy steel componentsfor high wear resistance
Sealing surfaces are often treated with:
Hard alloy surfacing (D507)for A28H
Cobalt-based alloys (Stellite)for A28Y
Critical components such as the valve seat, disc, and stem are processed usingCNC machining centers, ensuring:
High dimensional accuracy
Smooth sealing surfaces
Consistent product performance
Sealing areas undergo:
Fine grinding and lapping
Hardening or alloy overlay treatment
This significantly improveswear resistance and sealing reliability.
The spring is a key component determining valve performance. Manufacturers conduct:
Elastic modulus testing
Fatigue resistance testing
Precise calibration of set pressure
High-quality materials such as50CrVA alloy steelare commonly used to ensure stable long-term operation.
Each A28H/Y safety valve undergoes rigorous testing procedures before delivery:
Set pressure test
Sealing (tightness) test
Full-lift opening verification
Performance parameters typically meet:
Set pressure tolerance within ±3%
Controlled overpressure and blowdown values
These strict testing processes ensure compliance with standards such asGB/T 12241 and GB/T 12243.
The A28H/Y safety valve is widely used across various industries due to itshigh discharge capacity and strong adaptability.
Used in:
Refining systems
Gas pipelines
Storage tanks
The A28Y variant is particularly suitable forcorrosive or hazardous media, ensuring safe and stable operation.
Installed in:
Steam pipelines
Boiler systems
Power plant auxiliary equipment
Its full-lift design ensures rapid pressure relief in high-load conditions.
Applicable in:
Chemical processing plants
Mining and metallurgy
Machinery equipment
It protects critical equipment from pressure fluctuations and potential failures.
Used in:
Water supply and drainage systems
Urban construction pipelines
HVAC and building systems
Its reliability and adaptability make it a standard safety component in infrastructure projects.
As industrial systems become larger and more complex, there is growing demand for:
High-flow safety valves
Rapid-response pressure relief devices
Reliable full-lift designs
The A28H/Y series meets these requirements effectively.
China has established a strong position in the global safety valve market due to:
Advanced production technology
Large-scale manufacturing capacity
Competitive pricing
Manufacturers can supplystandardized products as well as customized solutions, meeting diverse global needs.
To improve durability and performance, manufacturers are increasingly adopting:
Corrosion-resistant alloys
High-performance sealing materials
Coated springs for harsh environments
This trend enhances product lifespan and reduces maintenance costs.
Modern customers require tailored solutions, including:
Custom pressure settings
Special material configurations
OEM branding
Chinese suppliers offer flexible production systems to meet these demands efficiently.
Choosing the right A28H/Y safety valve requires careful consideration of several factors:
A28H: Non-corrosive media
A28Y: Corrosive media
Ensure compatibility with system design pressure and safety requirements.
Full-lift valves are suitable for systems requiringlarge discharge capacity.
Select appropriate materials based on temperature, pressure, and medium properties.
Choose threaded or flanged connections based on installation conditions.
Install vertically for proper operation
Avoid back pressure at the outlet
Ensure unobstructed discharge
Regularly inspect sealing surfaces
Test opening pressure periodically
Replace worn springs or sealing components
Proper maintenance ensureslong-term safety and stable performance.
The A28H/Y Type Safety Valve is a high-performance, full-lift pressure protection device widely used in industrial systems requiringrapid and reliable overpressure relief. Itsrobust structure, advanced sealing technology, and wide material adaptabilitymake it suitable for a broad range of applications, from petrochemical plants to municipal infrastructure.
With strong manufacturing capabilities, continuous technological improvements, and flexible customization services,Chinese manufacturershave become leading suppliers of A28H/Y safety valves in the global market.
As industries continue to demand higher safety standards and operational efficiency, the A28H/Y safety valve will remain an essential solution for ensuring system reliability and protecting critical equipment worldwide.
