JW Winco’s AISI 316L (A4) stainless steel threaded plugs, magnetic plugs, and robust oil sight glasses


At first glance, the Fluid Fill / Drain Plugs offered by Winco as GN 742.5 appear to follow the established level of technology – except they are made of AISI 316L (A4) stainless steel. The plugs are available for thread from M14 to M33 and G¼ to G1 and are intended for especially corrosive environments. The screws have an embedded seal of fluorine rubber secured against loss or overloading. To minimize errors, they have icons on the front side clearly indicating whether the opening is for filling or draining.

The magnetic plugs GN 738.5 look similar, except they have an integrated bar magnet extending into the fluid to reliably capture any iron particles damaging gears.

Winco is introducing the fluid sight glasses GN 7440 as a premium addition to the longstanding variants of aluminum, brass, and plastic. GN 7440 offers the corrosion resistance of AISI 316L (A4) stainless steel and another special new feature: The glass sight glass is inserted into the stainless-steel body using a special thermal process. During cooling, the glass shrinks to create a hermetic and tight seal. The level of pretensioning makes it almost indestructible. This allows the oil sight glass to withstand even high pressures. Burst tests have shown that, depending on the temperature, the parts only fail at pressures above 400 bar. Thanks to the FPM seal, temperatures up to 356 °F (180 °C) are no problem; with a copper seal, even temperatures as high as 572 °F (300 °C) are withstood.

Notches integrated into the chemically resistant glass give reliable indication of the current liquid level. GN 7440 improves operational reliability since its sight glass will not burst spontaneously. It signals overloading with the formation of easily discernible small cracks allowing time to replace the oil sight glass before it fails entirely. Winco offers the premium sight glass in standard sizes from M16 to M42 and G? to G1¼. Other thread diameters are available on request. The same applies to the threaded plugs GN 742.5 and GN 738.5.
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