Profile: A V K Industries, Inc. offers in-line pressure relief valve testing devices. Our ultralite laptop portable in-line pressure relief valve testing devices help to verify the set pressure of safety relief valves in-line, without having to shut down a system or unit. Our ultrastar-LFM portable in-line pressure relief valve testing devices are microprocessor controlled lift assist devices designed to establish set pressure, in-line, on all spring loaded pressure relief valves, with an exposed threaded spindle.