Automotive

Customer
A.C. Rochester (Division of General Motors)

Application
Fuel Injector Nozzles

Background
This particular plant manufactures fuel injector nozzles for every G.M. car in the world. There are several parts made for a nozzle, all of which are small -1/8” diameter pins, discs that are 5/8” diameter by 1/8” high, etc.

Problem
They were using vapor degreasers with a freon liquid that was set to be banned (ozone depleting substance) and which was costing them $500,000 a year. They wanted to use aqueous systems but first they had to answer two (2) major questions:

1) The parts can’t be tumbled because of the damage tumbling would cause. Could a jet washer clean and dry a basket of small parts without tumbling?

2) Some of the parts were silica iron which rust in a New York second. Could an aqueous solution protect these parts from flash rust?

Solution
With nozzle and flow adjustments, a basket load of these small parts could be washed and dried without blowing them out of the baskets. A.C. Rochester loads their standard baskets called “boats” (15”L x 6”W x 4”H) onto the turntables arranged like spokes on a wheel. Each basket had a 2” deep pile of parts. A high concentration of amine-based rust inhibitor prevented rust. If the parts were going to be stored, they were placed in plastic bags impregnated with sodium nitrite.

System
An F-4000-P-ZX built to G.M. specifications. The system had an ARC-11 rinse stage and a 10 HP regenerative blower for drying. The wash tank was automatically refreshed after “x” minutes of wash time by adding water, overflowing into a side tank, and pumping the overflow to their water treatment system.

6/15/93