Portable Pump / Filter Unit Helps Precision
Machine Shop Cut Costs Dramatially

Hayn Enterprises, LLC (Rocky Hill CT), established in 1960, is a leading manufacturer of turnbuckles and cable hardware for the marine and architectural industries. Primarily machining type 316 stainless steel exclusively, they utilize 8 Swiss CNC machines, an Okuma mill, two CNC turret lathes, and a Mazak mill, all machining with cutting oil. Hayn engineers found that the condition of the cutting oil was contributing to some difficult quality and production problems.

According to Ted Beger, supervisor of the machine shop, fragments from the machining process were accumulating in the oil, and the these fragments were embedding in the 316SS during various machining operations. The result was thread galling and parts rusting. In addition, the fragments in the cutting oil were in turn accelerating the wear on the tooling, leading to poor tooling life and abbreviated filter life in the bag filters on the high pressure coolant systems.

While researching possible solutions to the problem of contaminants in the cutting oil, Hayn engineers visited a trade show exhibit of products by Keller Products, Inc. Keller supplies complete lines of equipment for filtering and purifying cutting oil and water-base coolant. The particular Keller unit of interest to the Hayn engineers was the PFA-1002, a portable pump/filter unit which is designed to remove solids from cutting oil or coolant in machine tool sumps without the need to pump out or shovel out the sumps. The PFA-1002 pump/filter unit contains a rugged, high flow rate air-operated diaphragm pump and a high capacity bag filter which removes solids as fine as 1 micron, mounted in a frame on a compact cart. With a recirculation rate of 20 gallons per minute, the PFA-1002 completely cleans fines and chips from a typical sump in minutes, and then is easily moved to another sump and set up to run simply by connecting a 1/4" compressed air line. With no electricals, the unit is inherently fireproof. The self-priming pump pulls the cutting oil from the sump through a large diameter vacuum hose into the bag filter and continuously pumps the filtered liquid back to the sump at high flow velocity. The force of the filtered liquid discharge scours the bottom of the sump and keeps chips and fines suspended in the oil for pickup by the inlet hose. Because the oil is not drained from the sump during the brief cleaning operation, the machine tool need not be taken offline for solids removal. Routine maintenance on the pump/filter unit consists of changing or emptying the filter bag when the pumping rate slows. In many applications, the filter bag may be emptied and reused a number of times.

The Hayn engineers purchased one PFA-1002 to service all twelve machines in the shop. Ted Beger reports that with the PFA-1002 in service tooling life has improved by 40 to 50 percent. The galling and rusting problems have been virtually eliminated so that they now have no scrap due to contaminated cutting oils. The filter bag life in the high pressure systems has tripled. He says that all these improvements were obtained at relatively low pump/filter unit operating. Ted Beger says, 'The PFA-1002 was a low cost and convenient solution to difficult and expensive quality and production problems. I would recommend this product to anyone doing precision machine work with straight oil."