Type A - with reflector
Type B - without reflector
GN743.7 Oil Level Sight Glass, Brass Float Glass, Conical Thread
The conical thread of the oil level sight glasses GN 743.7 makes a metallic seal possible. When tightening the conical male thread R it blocks itself with the appropriate cylindrical female thread Rp.
With the datum plane a the R male thread has the same thread diameter as the Rp female thread, so that it can be screwed in by hand. Stronger tightening using a tool increases the length of engagement and seals the screw connection.
Additionally a sealant (hemp or teflon band) is usually used. The R thread is roughened, so that the sealant does not shift when screwing in.
Oil level sight glasses GN743.7 can be used on pressurised tanks. Pressure and vacuum pressure test data is available.
Body - Brass MS, CuZn40Pb2
Reflector - Technoploymer (Polysulfon), temperature resistant up to 100 °C
Sight glass - float-glass
O-rings - rubber, NBR (Perbunan)