Fit-and-forget protection for low-pressure systems

A versatile new pressure relief valve for low pressure instrumentation applications up to 400 PSI (27.6 bar) has been launched by the Instrumentation Products Division of Parker Hannifin, the global leader in motion and control technologies.

CE marked and certified to the highest Category-IV level of the Pressure Equipment Directive (PED) the new HPRV valve is supplied pre-set to any of six pressure ranges from 10 to 400 PSI (0.7 to 27.6 bar). The chosen cracking pressure is laser etched onto the valve body at the factory. Another variant of this relief valve design is available for higher pressure applications.

The new HPRV valve provides a simple 'fit and forget' solution for building reliable safety, environmental and/or equipment protection into a wide variety of process and laboratory instrumentation applications - one that needs no testing or calibration by the end user.

Unlike some competitive products, Parker supplies each HPRV low pressure valve as a complete item including the spring that determines the cracking pressure, under a single order number to simplify purchasing. The valve is 100% PED certified, and requires no additional paperwork or approvals to use the product. Parker has additionally set up its manufacturing and assembly process to ensure short lead-times.

The valve has a 5.2 mm (0.203 inch) orifice. As standard, it comes with either twin-ferrule A-LOK or single-ferrule CPI compression tube fitting ends, eliminating threaded connections and the potential problems that are associated with using thread sealants such as PTFE tape. Other types of end connection may be specified to suit the installation.

The valve's outlet port can release over-pressures to atmosphere, or be configured to duct media to a safe place. The cracking pressure is determined by one of six factory-fitted springs. These provide a choice of six cracking pressure ranges: 10-25, 25-50, 50-100,100-150,150-225 or 225-400 PSI (0.7-1.7, 1.7-3.4, 3.4-6.9, 6.9-10.3, 10.3-15.5 or 15.5-27.6 bar). A locking wire may be fitted to secure the chosen pressure setting and guard against tampering.

O-ring seals adapt the HPRV valve for different types of media, and operating temperatures from -57 to 204 degrees C (-70 to +400 degrees F). Five choices of material are available: fluorocarbon rubber and nitrile rubber for general-purpose use, ethylene propylene or neoprene rubber for compatibility with a wider range of chemicals, or highly fluorinated fluorocarbon rubber which is compatible with a very wide range of chemicals.

Charles Harris, Business Development Manager for Parker Hannifin, comments: "The introduction of these low pressure options rounds out Parker's range of relief valves for process instrumentation applications, providing users with the means to select optimised and accurate protection for pressure-containing systems operating from 10 to 6000 PSI. The European Directive approval also gives us a distinct advantage over many of our key competitors."