Steam Turbine Gland Seal / Fins Clearances Testing Method (White Medical Adhesive Tape Method)
Steam Turbine Gland Seal / Fins Clearances, Role for Performance Improvement by Improvement in Clearances, Testing method of seal clearances (1) Medical tap method (2) lead Wire Method (3) Butt Clearance This is for Turbine Performance Improvement by Improvement in Heat Rate / Efficiency also Balancing of the Thrust.
1.) Method / Procedure for Seal fin Clearance (Seal Fin Cutting)
1.) White medical adhesive tape Method
2.) Lead Wire Method
3.) Butt Clearance
1.) White Medical Adhesive Tape Method:-
Paste white medical adhesive tape in multiple plies ( one single tape is of 0.25 mm thickness) of desired thickness proportionate to clearance required on the labyrinths of the seal and apply blue on it.
After this the Turbine Rotor is rotated by full revolution .
The fins which clears the tape i.e. which don’t rubs
The tape while rotation is deemed to be having clearance more than the combined thickness of the tape and Fin which rubs the tape is having clearance less the combined thickness of the tape.
The fins which rubs the Tape needs to be grinded suitably to get the desired clearance.
Above procedure could be repeated many times till the desired clearance is achieved.