High Efficiency - Supplementary loading system

Solutions for high plant efficiency

Tight to set pressure
Operating pressures up to 97% of set pressures
Low loss of medium during blow-off process

Technical data High Efficiency - Supplementary loading system

Set pressure		0.1 - 250 barg \| 1.5 - 3626 psig
Temperature		-40 - 550 °C \| -40 - 1,022 °F
Capacity		Orifice F- to X
Connections DIN EN 1092		DN 25 to DN 400
Connections ASME B16.5		NPS 3/4 to NPS 16
Body material		Gray cast iron, nodular cast iron, carbon steel , high-temperature carbon steel , stainless cast steel

Supplementary loading system for high back pressures at DESY in Hamburg.

A plus in clamping force

Industry / Application

Research center as end user

LESER products

Pneumatic option with high-performance safety valves

Challenge

Protection of a helium plant with extremely low temperatures of -273 °C, high back pressures of 60% and low set pressure of 0.5 bar

The research center Deutsches Elektronen-Synchrotron (DESY) has reduced the operating pressure for helium containers in the cooling system of the electron accelerator. However, the back pressures occurring in the blow-off systems could not be reduced to the same extent. As a result, the back pressure ratios for the existing spring-loaded safety valves were now unacceptably high at 60 percent. Since the set pressure is only 0.5 bar, standard bellows or pilot-operated Safetys valves were not an option. In addition, the helium plant has to be protected against very low temperatures of -273 °C. Another requirement: Adaptations to the existing plant were to be kept as small as possible.

The right solution from a wide range of configurations
LESER was able to offer the additional load as a solution to the DESY problem and thus won the tender for the project. With the additional load, a spring-loaded Safetys valve receives a drive for additional closing force. Air is used to build up pressure in a pneumatic piston as an extension of the spindle . During normal operation of the system, this pressure - together with the spring - counteracts the operating pressure under the disc .
The Safetys valves with pneumatic additional load have a higher tightness due to the greater closing force: they are tight up to the set pressure . This allows the system pressure to be increased. In the event of response, the valve is open for a shorter time due to the reduced opening or blowdown pressure difference . This reduces media loss. "We are very satisfied with the solution we selected with LESER ," says Dieter Mross, who is responsible for the project at DESY. "By making just a few adjustments, we were not only able to retrofit the existing system, but also to improve it significantly."