Parallel Back-Flow Safety Valve (also known as a Parallel Slide Check Valve or Non-Return Valve) is a specialized safety device designed to prevent reverse flow (backflow) in piping systems while minimizing pressure drop. Unlike traditional swing or lift check valves, it uses a parallel sliding disc mechanism to ensure tight sealing and rapid response to flow reversal.
TSV's exceptional quality starts with raw materials. We use certified, high-grade alloys (like WCB, CF8M, 316L) precisely selected for pressure, temperature, and corrosion resistance. Full traceability and material test reports guarantee integrity, forming the foundation of our valves' reliability and long service life.
TSV ensures valve reliability through high-accuracy machining verification. Using advanced machines, we meticulously validate every critical dimension and surface finish against strict tolerances, guaranteeing perfect performance and leak-free operation in every safety valve we produce.
To ensure TSV's safety valve performance testing is exceptional. Every valve undergoes rigorous functional, set-pressure, and seat-tightness tests under simulated real-world conditions. Certified to ASME and ISO standards, we provide full test reports and traceable data, guaranteeing proven reliability and compliance for your critical applications.
TSV's final inspection is the ultimate guarantee of quality. Every valve undergoes a comprehensive checklist review, including visual examination, dimensional verification, function testing, and documentation audit. This meticulous process ensures zero defects and full compliance before delivery.
The opening pressure of a safety valve is predetermined according to the compressor system's design specifications and operational requirements.
To guarantee adequate protection, the operation of safety valves in relieving excess pressure must demonstrate high dependability and operational consistency.
The safety valve needs to react quickly to sudden increases in pressure, opening without delay to discharge any overpressure.
Upon releasing pressure, the valve must be able to reclose tightly and maintain a reliable seal to avoid any leakage while operating under standard conditions.
The construction of safety valves requires the use of premium-grade materials to endure the operational stresses, thermal loads, and surrounding conditions present in compressor systems.
Safety valve, known as pressure relief valves as well, mainly has two types:
● Spring loaded safety valves
● Pilot loaded safety valves
● The combined discharge capacity of the safety valves must exceed the maximum steam flow rate that can pass through the boiler's outlet connection.
● The valve activates exclusively when the internal steam drum pressure exceeds its predetermined threshold.
● Common operational issues with safety valves often include seat and disc erosion, internal corrosion, contamination by foreign debris, simmering or chattering, leaky gaskets, and the loosening of fasteners caused by system vibration.
The advancement of engineering specifications calls for increasingly sophisticated designs to ensure zero leakage, optimized flow capacity, and minimal blowdown. These stringent performance requirements have led to the development of the safety relief valve as an evolution over traditional safety valves. The incorporation of dual adjustable control rings allows the valve to comply with stringent regulatory standards for high-pressure safety relief applications.
When the valve is shut, the nozzle or lower ring is positioned so its top edge lies just above the seating surface. This configuration traps the escaping steam and directs it upward against the disc. As a result, the steam is deflected outward by the upper rings, generating increased lifting force.
Lowering the upper regulating ring increases the deflection angle of the escaping steam, enhancing its reactive force on the disc. As a result, a larger pressure drop below the setpoint is required before the spring can reseat the valve, leading to longer blowdown. Conversely, raising the ring reduces both the reaction effect and the blowdown duration. This principle of utilizing flow-induced reaction forces enables the valve to achieve full capacity, accurate modulation, short blowdown cycles, stable performance, and extended seat service life.
Based on the media (air, gas, steam, liquid).
Set pressure, open pressure, and back pressure.
The valve must be sized based on the required capacity.
Operating conditions—including temperature, medium and environment—must be taken into account during selection.
Based on the operational characteristics.
Normal working pressure is the operating pressure of the system under full load.
The maximum allowable working pressure (MAWP) represents the highest permissible pressure under standard operating circumstances.
Set pressure, it is the pressure at which the valve starts to lift.
Overpressure refers to the amount by which the system pressure surpasses the valve's set point, initiating the lifting process.
These safety valves are primarily employed in systems handling compressible media, including steam or various gaseous substances.
The safety valve remains fully open until the system pressure returns to its normal operating level, at which point it closes.
The outlet sizes of a safety valve is typically larger in diameter than its inlet sizes.
A manually operated test lever is mounted on the exterior of the safety valve, typically at the top of the body, to permit regular functional verification.
This style of valve features a spring chamber vented to the outlet side. Variations in backpressure influence its operating behavior. As one of the most basic safety valve designs, these compact valves are commonly applied in low backpressure applications.
Balanced safety valves utilize bellows or similar mechanisms to counteract the influence of backpressure. These spring-loaded safety relief valves are typically installed in systems where backpressure accumulation in the discharge line may exceed the allowable overpressure limit of a standard valve. There are two primary designs of balanced valves: those employing a piston and those incorporating a bellows assembly.
A pilot-operated safety valve functions as a pressure relief device where a small, self-actuated pilot valve controls the opening and closing of the main relief element. These valves fall into two main categories: diaphragm and piston types. Diaphragm-operated valves are typically suited for low-pressure services, while piston-type valves employ a piston as the primary sealing component and are regulated by an external pilot mechanism.
TSV’s manufacturing and quality verification processes are supported by state-of-the-art equipment, ensuring full compliance with a wide range of industry standards.
With decades of industry expertise and a skilled team of engineers and technicians, we guarantee exceptional precision and consistent product quality.
We are dedicated to delivering dependable service and high-standard products, backed by our unwavering customer support on every order.
Staffed with numerous senior engineers, the company is complemented by superb facilities and sophisticated technology.
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E-mail: info@tsv-valve.com
Telephone: +86-13695850057
Whatsapp: +86-13695850057
Address: TianSheng Industrial Park,Dong'ou Industrial Zone,Oubei Town,Wenzhou City,Zhejiang Province,China
