TECHNOLOGY
that , for reasons of efficiency and safety , needed to be regulated . The regulators available on the market were not precise enough so he devised a completely new method of controlling gas and developed a series of products based on this technology .
The flow “ represents the first genuine innovation in this type of valve design since the Victorian age and the brilliance of it hinges on the fact it uses a direct sensing piston actuator , rather than a diaphragm to control pressure ,” explains Chris Leonard , Oxford Flow ’ s Business Development Director . “ Removing the diaphragm eliminates the main source of failure in valves ,” he adds .
A typical regulator works by using a diaphragm that constantly modulates as it controls pressure ,
“ The brilliance of it hinges on the fact it uses a direct sensing piston actuator , rather than a diaphragm to control pressure .” and therefore needs to be flexible in order to provide accurate control . This flexibility is normally provided by a limited range of elastomers , which , because of their elasticity , are prone to fatigue , embrittlement and erosion . This , in turn , necessitates repair and replacement . By replacing the diaphragm with a direct sensing piston actuator , the main reason for valve failure is eliminated and the design is greatly simplified .
“ One side of the piston is exposed to downstream pipeline pressure , while the other side is balanced against a pressure cavity controlled by a pilot regulator ,” says Leonard , “ The piston actuator operates over an optimised feed-hole configuration to provide precise , stable control across the entire operating range . During operation , the piston moves inward , reducing the size of the cavity when the downstream pipeline pressure exceeds that within the pressure cavity set by the pilot regulator .
The movement of the piston actuator in closing reduces the flow rate to maintain a stable downstream pressure . When demand increases the downstream pressure falls below that set by the pilot and the
18 October 2016