ROCKLEDGE, Fla. - HVACR service technicians can enhance their nitrogen safety use by ordering a free combination check-valve/pressure-relief valve. Mainstream Engineering, which manufactures Qwik System Flush (QSF), is financing the $150,000 relief valve giveaway program until Sept. 30. The company is also offering a free “Nitrogen Safety Bulletin” publication for download at as part of its efforts to protect service techs in the field. The free relief valve is designed to connect to the ¼-inch flare fittings of Mainstream’s flushing agent canister access valve and acts as a third line of defense against accidental over-pressurization of the aerosol canister.

“The first two lines of defense against nitrogen accidents are never, under any circumstances, connect a nitrogen bottle to an aerosol canister (via manifold gauges) or an unattended sealed system; and read the flushing agent manufacturer’s directions for proper usage,” said Robert P. Scaringe, PE, Ph.D., president.

Flushing out loose debris with nitrogen followed by a flushing agent cleaning recently has become a popular service technique especially for preparing irreplaceable linesets for R-22 to R-410A system conversions. Totally flushing and removing potential sludge-producing contaminants from irreplaceable linesets is considered integral to a conversion’s success and the system’s lifecycle.

However, some technicians not educated in nitrogen safety endanger the service jobsite by wrongly connecting both nitrogen tanks (2,000-psi) and flushing agent canisters (ranging in capacity from 270-psi for most brands to 391-psi of QSF) to manifold gauges. An accidental turn of the wrong manifold valve, a leaky valve, or a faulty nitrogen pressure regulator can accidentally over-pressurize the canister, the connecting hose, or the refrigeration system. Flushing agent canisters should be connected directly to linesets without the use of manifold gauges, according to Scaringe.

The free safety kits are available by calling 321-631-3550 or visiting and selecting the “Claim Your Free Can Access Valve Safety Kit” icon.

Publication date:08/02/2010