Anderson Greenwood valves are the industry standard for overpressure protection across oil and gas, chemical refining, power generation, and process industries. When system pressure threatens equipment integrity or operator safety, these valves discharge excess pressure before catastrophic failure occurs.
Selecting the right valve type is critical for system efficiency and safety. Anderson Greenwood’s portfolio spans from direct spring operated designs to sophisticated pilot operated configurations for demanding environments.
To explore the full spectrum of pressure management solutions, explore the Natradesource Product Catalogue.
Direct spring operated pressure relief valves represent the most straightforward approach to overpressure protection. In these Anderson Greenwood designs, a calibrated spring resists system pressure until it exceeds a predetermined set point, whereupon the spring compresses and the valve opens to relieve excess pressure. This mechanical simplicity makes direct spring operated valves the entry point for many applications.
The Series 60 and 80 direct spring operated relief valves deliver premium performance across diverse industrial applications. These valves employ patented internals and soft seats for accurate pressure control. They excel in straightforward on-off applications, avoiding the complexity of pilot operated alternatives.
The Type 81 features an inert plastic seat, ideal for cryogenic, high set pressure, and chemically active applications. Operating pressures reach 10,000 psig with temperatures up to 515°F. The Type 83 employs an elastomer seat for gas, vapour, liquid, or thermal relief applications. The Type 86 variant handles steam service and high-capacity requirements.
Pilot operated pressure relief valves employ a two-stage mechanism where a small pilot valve controls the main relief valve. This design enables a small pilot stage to command significantly higher flow volumes and pressure capacities, delivering exceptional efficiency across demanding applications.
The Series 200 suits gas, vapour, and mixed-phase services, including dirty or wet applications. It maintains tightness to 95% of set pressure. The Series 400 offers increased system output with 98% tightness. Series 400 incorporates soft seats and modulating action for full valve lift with minimal overpressure, minimising product loss. Both series accommodate temperatures from -423°F to +600°F with set pressures from 15 to over 6,170 psig.
The Anderson Greenwood Series 500 modulating pilot operated relief valve delivers premium tightness whilst handling temperatures from minus 65°F to plus 515°F. This series uniquely employs all-plastic seats and seals, providing exceptional chemical compatibility with the lading fluid. The Series 500’s resilient seats eliminate expensive metal seat lapping, reduce product loss through superior pre and post-relief cycle tightness, and minimise noise through modulating action during system upset.
The Series 700 and 800 variants extend Anderson Greenwood’s capabilities further, offering pilot operated performance specifically engineered for high-temperature steam, hot oil, and severe thermal relief applications. These series maintain bubble-tight seating whilst tolerating extreme temperature variations, rendering them indispensable in power generation, thermal processing, and complex multi-phase refining applications. Consulting specialists such as those available through Natradesource’s Fisher and Bray valve divisions provides access to engineering expertise specific to challenging high-temperature service conditions.
Beyond standard series, Anderson Greenwood manufactures specialised valve configurations and system solutions addressing unique industrial challenges. These innovative designs solve difficult problems that conventional single-valve approaches cannot adequately address.
The Anderson Greenwood Safety Selector Valve provides an ingenious solution for redundant pressure relief systems, enabling safe switching between active and standby relief devices whilst maintaining continuous overpressure protection. Traditional redundant systems require bulky, expensive piping fabrications with multiple vessel penetrations and mechanically linked block valves. The Anderson Greenwood Safety Selector Valve eliminates this complexity through a unique design incorporating less than 3 per cent pressure drop to the active pressure relief valve inlet, in accordance with ASME Section VIII and API RP520 guidelines.
The selector valve’s foolproof locking mechanism prevents inadvertent closure of the wrong valve during switchover operations, a critical safety feature in facilities where operator confusion could prove catastrophic. Tandem Safety Selector Valve systems allow simultaneous selection of both inlet and outlet selector valves, ensuring complete switchover integrity. These systems are pre-assembled at the factory in coordinated configurations, requiring only flanged inlet and outlet connections in the field. The interlocking mechanism employs a red pointer indicator and simple lock hasp design requiring no special tools for operation.
The Anderson Greenwood Series 90/9000 pilot operated pressure relief valves provide extremely accurate valve setting and ultra sensitive response with set pressures as low as 4 inches water column (10 millibars), rendering them ideal for cryogenic and non-cryogenic storage tank applications. These valves accommodate temperatures ranging from minus 320°F to plus 200°F, addressing the unique requirements of liquefied gas storage, liquid nitrogen systems, and oxygen service where conventional relief valves lack adequate sensitivity.
Tank blanketing regulators such as the Anderson Greenwood Trans-Zero Regulator provide an inert gas blanket over liquids in storage tanks, preventing oxidation, maintaining product quality, and reducing environmental emissions. The Trans-Zero regulator achieves bubble-tight shut-off whilst reducing blanketing gas from 14 barg to 12.5 millimetres water column in a single step, delivering economical, low-maintenance operation across diverse storage applications. For advanced thermal control and instrumentation solutions, exploring Bray and Bettis options through Natradesource expands possibilities for integrated systems.
Anderson Greenwood valves set the industry standard for overpressure protection. From straightforward direct spring operated Series 60 and 80 valves to sophisticated pilot operated Series 200 through 800 designs, Anderson Greenwood’s comprehensive range ensures solutions exist for virtually every industrial application. By understanding valve type distinctions and matching specifications to application requirements, operators ensure reliable systems that meet both regulatory and operational expectations.
For comprehensive technical support and expert guidance on Anderson Greenwood valve selection, contact Natradesource’s pressure management specialists.
North American Trade Source (NATS) is a trusted distributor of premium oil and gas equipment, committed to delivering innovative solutions and exceptional customer service worldwide.
