ST Instructions

Installation Instructions

On this page only the installation of the ST-G is depicted. The installation concept remains the same for all three drain fitting types: the ST-G, ST-K and ST-R.

See also :

 -  Installation video ST-G (larger funnel, rectangular ducts only) and the

 -  Installation Video ST-K (small funnel, rectangular and round ducts).

Drill a hole in the duct wall:
ST 1/2" = 22 mm Ø
ST 3/4" = 28 mm Ø
ST 1" = 35 mm Ø
ST 1 1/2" = 49 mm Ø

Apply some sealant around the hole if the duct wall surface is uneven or dirty, or if a higher tightness must be achieved.

For the installation on thicker duct walls the ST Funnel-Puller should be used beforehand, as the drain fitting might otherwise break.

Insert the drain fitting into the hole from inside the duct.

Place the funnel, conical washer or saddle funnel on the fitting followed by the nut from outside the duct. 

The flat area on the fittings allows to keep them from rotating using pliers and without damaging its thread. Applying some grease between the nut and the fitting eases the tightening operation. A special anti-seize lubricant should be used on stainless steel drain fittings. Tighten the nut till the duct wall is slightly deformed to form a funnel-like area. Do not overtight, especially the ST-K, as the conical washer might break.

The ST Holding-Wrench allows tightening the drain fittings easily without damaging the threads. It is especially recommended when a PTFE seal (optional) is used to increase the drain fitting's liquid tightness. The assembly is carried through as indicated above, except when the Holding-Wrench is used instead of the pliers. Please make sure that the lever faces the fitting‘s flat surface, and then tighten the nut using a wrench.

ST-G Installation Video

ST-K Installation Video











Double Wall Ducts