Valve Problem Solved, Medical Product Delivered

A custom valve assembly solved a critical manufacturing issue, permitting the customer to offer a new product to the emergency medical technology market by providing critical pressure monitoring when delivering a CO2 - O2 mixture to patients suffering from toxic gas or smoke inhalation.

A problem existed for the customer, a major manufacturer of respiratory care and critical care products. Through use of its proprietary technology, equipment to be developed would be a portable rebreather for emergency medical treatments. The device used a control assembly to deliver CO2 and O2 to a separate mixture valve, then deliver it to the patient. If a special valve assembly could be created that met critical design requirements beyond the manufacturer's core competency, it would open up new markets for the company.

The customer is a world leader in respiratory technology and has established its core competency as a designer of innovative equipment. For the company, after it had designed the new system, its functionality and size presented a barrier to further development.

Needed was a valve assembly that would operate at 30 - 40 psi, with On/ Off capability no greater than ±3 psi. Leakage could be no greater than 1.9 cm³/hour. Too, the assembly would have to meet specific size and weight requirements for portability.

The company contacted Humphrey Products Co, for help in developing a finished product that would meet the critical requirements and specifications.

Humphrey's Engineered Solutions team approach began with a Humphrey engineer working directly with the customer's engineering department to identify all the requirements and opportunities to improve the product. In this case, although the customer had developed a design for the respiratory device, its engineers identified both size and response time as critical.

Addressing functionality, the Engineered Solutions team identified valve hysteresis as the key to improved response time and, consequently, critical pressure maintenance. The Humphrey solution was use of its 310 short stroke valve, piloted by an air cylinder. Used in pairs, one cylinder would provide the necessary metering control, while the other would provide a critical warning signal to an air horn in the event the gas supply dropped below the required pressure.

The Humphrey pilot-operated 310 Valves with short stroke solved the hysteresis problem, enabling the device to precisely meter gas flow and respond quickly to any variations in pressure. Adjustable, spring-loaded, single-action cylinders controlled the valves.

To meet the customer's device size requirements, Humphrey developed a custom manifold that incorporated a manual needle valve flow control, regulators, gauges, shutoff valves, filters and check valves.

One of the check valves was designed as a redundant low-pressure warning device, sending a signal to the air horn which had a fixed orifice. The Humphrey manifold, together with the company's mixer valve, met the desired size requirements for portability. The entire unit was assembled and100% tested at Humphrey. TMD

To learn more, call Humphrey at 269-381-5500 or visit the web site at www.humphrey-products.com.