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Industrial systems handling both gaseous and liquid media face a unique challenge: finding a relief valve that provides consistent safety across different fluid states. The Xiazhao TOS-4C2-01-P / 3/4D1 API Relief Valve is engineered to meet this need, offering a dual-media universal design that complies with the globally recognized API 526 and API 527 standards. Whether protecting an air compressor, a steam pipeline, or a liquid chemical transport system, this valve ensures reliable pressure relief and zero leakage under the most demanding industrial conditions.
Advanced Versatility: Dual-Media Engineering
The Universal Gas & Liquid Solution
Traditional safety valves are often limited to a single state of matter—either compressible gases or incompressible liquids. Using a gas valve for liquids often leads to "chatter" or instability, while liquid valves may fail to provide the tight seal required for gaseous media. The Xiazhao TOS-4C2-01-P solves this by utilizing an optimized internal trim designed for dual-media universal service. This allow a single valve model to protect systems involving compressed air, steam, nitrogen, water, or oil, significantly reducing inventory complexity and procurement costs.
The valve’s internal geometry is calibrated to provide stable lifting and rapid resetting regardless of the medium's density or viscosity. This versatility makes it an ideal choice for facilities that operate integrated processes where gas and liquid lines run in parallel, ensuring a uniform safety standard across the entire plant.
Precision Pressure Control and Calibration
Accuracy is paramount in low-to-medium pressure applications. The TOS-4C2-01-P is designed for set pressures ≤1.8MPa (260psi). Each valve undergoes rigorous spring testing to ensure that it opens precisely at the designated set point and closes decisively once the pressure is relieved. This precision prevents over-pressurization that could damage pressure vessels or cause system-wide failures, while also minimizing "simmering" that leads to unnecessary medium loss.
Compliance with International Safety Standards
API 526: Standardized Design and Performance
Adherence to API 526 ensures that the Xiazhao relief valve meets standardized dimensions, orifice sizes, and pressure-temperature ratings. This standardization simplifies the engineering phase, as the valve’s discharge capacity can be accurately predicted and integrated into system safety calculations. The 3/4" fixed flange (RF) connection follows ASME B16.5 specifications, providing a robust and leak-free interface even in systems subject to high vibration.
API 527: Ensuring Zero Leakage
The "Seat Tightness of Pressure Relief Valves" standard (API 527) is the benchmark for sealing performance. Xiazhao TOS-4C2-01-P valves are manufactured with precision-ground seats and discs, ensuring zero leakage up to the set pressure. This is particularly critical in steam and chemical systems where even a minor leak can lead to significant energy waste, environmental hazards, or personnel safety risks.
Durable Construction and Material Science
Superior Material Selection
To handle temperatures up to 200°C and resist various corrosive media, Xiazhao offers a range of high-grade materials. While the standard internal parts are crafted from 316L Stainless Steel, the valve body can be customized with WCB (Carbon Steel), CF8, or CF8M (Stainless Steel) depending on the chemical compatibility required. For high-frequency or high-temperature applications, Inconel X-750 springs are available to maintain consistent tension and prevent fatigue.
Safety-First: No-Handle Design
The TOS-4C2-01-P features a "No-Handle" construction, emphasizing fully automatic operation. In many industrial environments, manual handles pose a risk of unauthorized tampering or accidental discharge. By removing the manual lever, Xiazhao ensures that the valve operates purely based on the physical pressure dynamics of the system, making it perfect for unattended or remote-controlled industrial sites.
Technical Specifications
| Item | Specification |
|---|---|
| Model | TOS-4C2-01-P / 3/4D1 |
| Connection Type | 3/4" Fixed Flange (RF) |
| Set Pressure | ≤ 1.8 MPa (260 psi) |
| Temperature Range | ≤ 200°C |
| Applicable Media | Gas (Air, Steam), Liquid (Oil, Water) |
| Standards | API 526 & API 527 |
FAQ
Why is a "Dual-Media" valve better than a specialized one?
A dual-media valve like the TOS-4C2-01-P offers operational flexibility. It eliminates the need for different valve types on a single site, reduces potential installation errors (installing a liquid valve on a gas line), and lowers the cost of carrying spare parts. It is designed to perform safely regardless of whether the medium is compressible or incompressible.
What does API 527 compliance mean for my system?
API 527 compliance guarantees that the valve has passed stringent seat tightness tests. This ensures that the valve will not leak or "weep" when the system pressure is below the set point, preventing the loss of valuable gases (like Nitrogen) or the escape of hazardous liquids.
Can this valve be used in corrosive environments?
Yes. While the standard build is highly durable, Xiazhao provides customization options for the valve body and internal trims (e.g., CF8M stainless steel) to resist specific chemical corrosion, ensuring a longer service life in harsh environments.
Need a reliable API relief valve for your facility? Contact the Xiazhao Valve Technical Department for expert selection support and customized pressure calibration today.
