BFP Jacket Cooling

In thermal power plant 2 types of M/S bhel make BFPs are used.one is KHI & another is FK series.In FK series there is no wormup required because its design is barrel types which makes the pump thinner helps to get equal heating of inner and outer casing with respect to rotor.

Balance leak off line is always connected to suction line.

Bfp mechanical seal cmprises of seat &rotating disc in a chamber from where only leakage water flowing out and enter into its suction line.This entire sustem has been cooled by making water jacketing.

Is it that KHI is old German models with Kicker stage for Desuperheating? and FK series is without kickerstage.