Cryogenic Danger Zone: Preventing System Failure from Particulates & Debris
Did you know that over 99% of cryogenic relief valve failures are due to a build-up of particulates, dirt and debris? And that tank slag, Teflon tape, and dirt are the most common culprits? When these contaminants build up in valves, they prevent the valves from re-seating properly. At best, a blocked valve results in minor leakage requiring valve replacement. At worst, a fully blocked relief valve leads to overpressurization causing dangerous and life-threatening system failure.
To prevent this, traditional valves must be regularly checked and replaced frequently, resulting in excess system maintenance time and costs. The engineers at Generant saw this problem as an opportunity to not only reduce the number of leakages and system disruptions caused by clogged valves, but to also improve cryogenic safety overall.
In 2000, Generant introduced a key design feature called the Dirt Guard system, a built-in device that prevents dirt and debris from interfering with the valve’s reseat precision. Ideally suited as a “blocked line safety” in cryogenic systems, the Generant CRV Series is a spring reference over pressure protection device. As the valve starts to open, the spring gives way and allows the poppet to fully open, allowing pressure from the bottom to escape out through the top, either to the atmosphere or further downstream.
Unique to the CRV’s design is a series of holes around the bottom of the poppet. Inside, a screen captures any particulates before they can cause trouble. This enables a much longer valve lifespan, with current recommendations to check and switch out valves every 4 to 5 years. The seat and poppet geometry, combined with optimized spring ranges provide high flow rates with minimum pressure accumulation.
The CRB version includes an “Integral Bleed” valve for safely venting valve inlet pressure. This is a much safer option for bleeding off pressure to service the system than loosening pressurized connections to bleed the system down, which is much more dangerous. The CRB option comes with a Monel 400 fully-retained venting screw that’s easily opened with a standard 5/64” allen wrench. Fluid is then safely diverted sideways away from the technician.
The CRV series comes in all brass or in stainless for high-purity applications, and both come cleaned and packaged for oxygen service. Valves are supplied with flourosilicone seals for set pressures from 10 to 49 PSIG (0.7 to 3.4 Bar) and PCTFE seals for set pressures from 50 to 750 PSIG (3.5 to 51.7 Bar). Set pressures are permanently locked to prevent tampering in the field.
- Available CE marked for the requirements of the Pressure Equipment Directive
- Exclusive Dirt Guard poppet extends valve life and ensures reliability
- Optimized for high flow with excellent reseat performance
- Locked setpoint prevents tampering
- Configurable to discharge to atmosphere or to a wide range of piping configurations (optional deflector cap for diverting exhausted gas)
- Integral bleed valve option for safe and easy venting of inlet pressure
- 100% factory tested for leakage, crack and reseat performance
- Oxygen service compatible