Xiazhao Valve API Relief Valve 3/4" Gas/Liquid Universal | Set Pressure ≤1.8MPa | TOS-4C2-01-P / 3/4D1 | API 526 & 527 Standard

Need to protect both gas and liquid systems? Xiazhao TOS-4C2-01-P / 3/4D1 API Relief Valve features a dual-media universal design, solving overpressure protection needs for multiple media with one valve. The set pressure is precisely adjustable below 1.8MPa, with temperature resistance up to 200°C. The fixed flange strictly complies with API 527 sealing standard to ensure zero leakage; the design meets API 526 for accurate discharge area. Widely used in air compressors, gas pipelines, steam systems, oil pipelines, pressure vessels, and water systems. No handle design, fully automatic pressure relief, reliable and durable. Click to learn why this valve can meet both gas and liquid working conditions and comply with international API standards!

Why Do You Need a Dual-Media (Gas & Liquid) API Relief Valve?

In industrial sites, you may face multiple working conditions simultaneously:
● Gas Systems: Compressed air pipelines, steam systems, nitrogen pipelines need to prevent explosions caused by excessive pressure.
● Liquid Systems: Oil transportation, water pipelines, liquid chemicals need to prevent water hammer damage and overpressure leakage.
Traditional safety valves are often dedicated to one medium — gas valves may flutter when used for liquids, and liquid valves may have poor sealing when used for gases. This means you need to purchase different valves for different systems, increasing inventory costs and selection difficulty.

Xiazhao TOS-4C2-01-P / 3/4D1 API Relief Valve is specifically designed to solve both gas and liquid working conditions.

Core Advantage Analysis of Main Image

Advantage 1: Dual-Media (Gas & Liquid) Universal, One Valve for Multiple Needs
Pain Point: Factories have both air compressor systems and liquid pipelines, requiring separate purchase of different valves, leading to complex selection and high inventory pressure.
Xiazhao Solution: TOS-4C2-01-P / 3/4D1 adopts an optimized dual-media internal valve design, passing both gas flow certification and liquid flow certification. Whether it is compressible fluid (gas/steam) or incompressible fluid (oil/water), it can achieve stable lifting and quick reset.
Customer Benefit: One valve covers multiple working conditions, simplifies the procurement process, and reduces spare parts inventory costs.

Advantage 2: Strictly Complies with API 527 Sealing Standard, Ensuring Zero Leakage
Pain Point: Unsealed relief valves cause continuous medium leakage, which is both wasteful and dangerous.
Xiazhao Solution: The flange connection design of this product fully complies with API 527 standard, which specifies the sealing performance requirements of valves under set pressure. The precision-ground valve seat and disc ensure true zero leakage below the set pressure.
Customer Benefit: Eliminates medium waste, meets environmental protection requirements, and ensures system safety.

Advantage 3: Precise Set Pressure, Freely Adjustable Below 1.8MPa
Pain Point: Low-pressure systems (such as below 1.8MPa) have high requirements for the sensitivity of safety valves, and ordinary valves may act inaccurately.
Xiazhao Solution: The spring has undergone strict testing and calibration, and can be accurately set to the customer's required set pressure (any value below 1.8MPa), ensuring timely opening when overpressure occurs and quick closing when pressure drops.
Customer Benefit: Precisely protects system pressure, avoiding misoperation or refusal to operate.

Advantage 4: Fixed Flange, Reliable Installation, Complies with API 526 Design
Pain Point: Although adjustable flanges are flexible, they may loosen under long-term vibration, posing a leakage risk.
Xiazhao Solution: This product adopts a fixed flange, which is more firm and reliable in connection, eliminating the leakage hidden danger caused by loosening. The overall design complies with API 526 standard, ensuring accurate discharge area and sufficient structural strength.
Customer Benefit: Once installed, it is worry-free, reducing maintenance frequency, especially suitable for high-pressure or severe vibration working conditions.

Advantage 5: No Handle Design, Fully Automatic Pressure Relief, Preventing Misoperation
Pain Point: Valves with handles may be misoperated when unattended, leading to accidental pressure relief.
Xiazhao Solution: This product has no manual discharge handle and is a fully automatic relief safety valve, which is completely controlled by system pressure to open and close, avoiding the risk of human misoperation.
Customer Benefit: Improves the degree of system automation, especially suitable for unattended or remote control scenarios.

Advantage 6: Optional Materials, Adapting to Various Corrosive Working Conditions
Pain Point: Standard materials are not corrosion-resistant, resulting in short valve service life.
Xiazhao Solution: Valve body materials are optional: WCB, LCC, CF8, CF8M; internal parts are standard 316L stainless steel; springs are optional 304 stainless steel or Inconel X-750, meeting the anti-corrosion and temperature resistance requirements of different media.
Customer Benefit: Choose the most economical material according to the actual medium, extending the service life of the valve.

Application Scenarios

TOS-4C2-01-P / 3/4D1 relief valve is widely used in the following equipment and pipelines that require overpressure protection:

Dimensions & Detailed Parameters

Why Choose Xiazhao Instead of Other Brands?

Because we are driven by both "technology + quality" to save you worry completely:

● Standard Compliance: Strictly follow API 526 design and API 527 sealing standards. Each valve undergoes factory sealing testing to ensure reliable performance.
● Selection Support: Not sure which material is suitable for your working conditions? Our technical department can provide selection suggestions and even drawing confirmation to ensure that the valve you buy is 100% applicable.
● Customization Capability: Set pressure, valve body material, internal part material, and spring material can be customized on demand to meet special working condition requirements.
● Logistics Guarantee: After the order is confirmed, the logistics department provides the optimal transportation plan to ensure that the goods arrive safely and on time.

Take Action Now

If your system needs a reliable, standard, and universal relief valve that meets the following conditions:

● Coexistence of gas and liquid media
● Set pressure below 1.8MPa
● Strict compliance with API 527 sealing standard
● No manual operation required, fully automatic pressure relief

Contact the Technical Department of Shanghai Xiazhao Valve now!

Let us use TOS-4C2-01-P / 3/4D1 to provide the most reliable overpressure protection for your equipment.