Pressure relief valves in hydraulic accumulator circuits
Hydro-pneumatic accumulators are considered in part as a safety-related component due to their use as accumulators in hydraulic applications.
The use is therefore specified in various legal regulations (country-specific) and standards (2014/68 / EU).
One of the requirements of the guidelines is to protect the accumulator circuits against pressure peaks and overload.
This is achieved by pressure relief valves, which should meet the following requirements:
- Reliable operation
- Robust design
- Vibration resistance -> Stable function
- Rapid response to pressure changes
- Low leakage
To ensure reliable operation, direct-operated pressure relief valves are used in most cases. These are - in contrast to the pilot-operated pressure relief valves - less sensitive to contamination and have lower leakage.
There are additional requirements that should be followed by the design of the pressure valve:
- Damping of the valve cone with a suitable degree of damping, while complying with the valve stability and reaction speed
- Max. overloading of the system pressure of 10% of the set opening pressure (acc. Directive 2003/26 / EU + ISO4126-1)
- Verification of the reliable function and continuous monitoring by a named person
As a well-known manufacturer of hydraulic valves, control blocks and complete hydraulic systems, ARGO-HYTOS extends its product portfolio to include the pressure relief valve SR1A-B2, which was generally designed for use in hydraulic accumulator circuits.
This is a direct-operated pressure relief valve in screw-in design 7 / 8-14UNF. The structure of a poppet valve ensures minimal leakage when the valve is closed. By optimizing the damping behavior, a very good valve dynamic could be achieved while maintaining a stable function. The maximum operating pressure is 420 bar, the maximum flow rate is 60 l/min. For a precise pressure setting, 7 valve pressure levels are at the customer’s disposal. The opening pressure can be adjusted in the respective pressure level range by an adjusting screw and secured with a lock nut. It is also possible to obtain the valve in preset condition (setting sealed).
With regard to the surface protection, the valve body and the adjustment screw are zinc-coated. The sleeve and the seat are protected by carbonitriding, which further optimizes the mechanical characteristics.
In order to be able to work in limited work spaces, the plastic cap was adjusted. The seals, either NBR or FKM enable the use of the valve at -30 °C up to +120 °C. The valve was certified by the TÜV Süd according to the application for hydraulic accumulator circuits.
In summary ARGO-HYTOS launches a high-quality product that combines the best cost / benefit ratio with reliable function and long service life.