<P> Another way to avoid scaling in the HP boiler is to use steam alone to transfer the heat from the fire ; steam can not of course deposit scale . Saturated steam from an HP steam generator was pumped through HP superheater tubes which lined the firebox . There it was superheated to about 900 ° F ( 482 ° C ) and the pressure raised to 1,700 psi ( 11.72 MPa ) . Only a quarter of this was fed to the HP cylinders ; the rest was returned to the steam generator where its heat evaporated more water to continue the cycle . </P>
<P> Another way to avoid scaling in the HP boiler is to use steam alone to transfer the heat from the fire ; steam can not of course deposit scale . Saturated steam from an HP steam generator was pumped through HP superheater tubes which lined the firebox . There it was superheated to about 900 ° F ( 482 ° C ) and the pressure raised to 1,700 psi ( 11.72 MPa ) . Only a quarter of this was fed to the HP cylinders ; the rest was returned to the steam generator where its heat evaporated more water to continue the cycle . </P>
maximum steam pressure in locomotive boiler in bar
maximum steam pressure in locomotive boiler in bar
1,700 psi ( 11.72 MPa )
1,700 psi ( 11.72 MPa )