Founded in 1945 in the Bronx, NY by two naval engineers, Sealed Unit Parts Co.,Inc (SUPCO) originated as a service company for refrigeration systems. These systems were "sealed", in that, when service was needed, the repair was done invasively. The desire to overcome these traditional methods was the impetus to the development of the patented "Bullet" valve in the 1950's.

SUPCO developed the first electronic vacuum gauge in 1990. The VG60 removed the uncertainty of analog technology for the growing need to measure this key system characteristic. During the latter part of the decade, master distributor partnerships for product lines, such as Therm-o-disc components, bolstered SUPCO's position as a key supplier to the HVAC/R and Appliance wholesale distributors.