A valve manufacturer has commissioned a room with clear vinyl walls and a HEPA air filter in which it will clean, inspect, and calibrate valves before they are installed on oxygen lines in labs and clinics. Clippard Instrument Laboratory Inc., Cincinnati, Ohio (clippard.com) has just put the finishing touches on its lab, one it considers the first of its kind in the U.S. The company designed the room based on several ASTM specifications and commissioned it August 1.

“Facilities that use pure oxygen, such as hospitals and labs, want to be absolutely sure nothing in them will start a fire,” says Clippard Industrial Engineer Steve Schutte. Fires fed by pure oxygen can burn almost anything.

At first glance, the enclosure looks like a clean room: walls are clear, a sticky mat at the door removes dirt from shoe soles, and a roof-mounted fan and HEPA filter keeps the room at a positive pressure.

Schutte adds that it's not a clean room in the strictest sense of the term. Lab personal will not wear the traditional bunny suits common to clean rooms. However, they will have to wear lab coats and gloves.

Before valves are assembled, component parts must complete a thorough cleaning and inspection. “Parts are ultrasonically cleaned in a hot, dilute solution of oxygen-compatible cleaner in purified water, then rinsed and dried with heat. Small ports and holes will be blown-off with compressed nitrogen, not shop air. Parts are then inspected under white and ultraviolet light to insure the absence of particulate and hydrocarbon contamination,” says Schutte. Many contaminants not normally seen under white light will fluoresce under UV light, making them easily visible. Parts with dirt will be removed and returned to the ultrasonic cleaner.

Afterwards, technicians will assemble, test, and calibrate the valves. Each finished valve will be heat-sealed in two clear plastic bags with an identifying label adhered to the outer bag.

Schutte cautions that companies performing similar actions will not get the same results that his lab does because each valve is calibrated after assembly. “Another firm could take the valves apart and clean the components. But when a valve is taken apart and reassembled following calibration there is no guarantee the valve will perform the same way. Our process lets end users immediately place a cleaned, calibrated valve into their process.”

To validate valves for oxygen service, the company assessed some 14 valve parts for six ignition mechanisms. The valves intended for service in oxygen environments have been slightly redesigned to eliminate the use of organic adhesives or lubricants. Not every valve the company makes will receive this treatment, according to Schutte.