The Industrial Boiler Drum Level control loop is to maintain the drum level within the prescribed limit. Simply regulating the Boiler Feed Water Control Valve regulates the boiler drum level. The drum level is measured by using level transmitter. The level signal is compared with fixed set value of level controller. Whenever there is a sudden rise in the steam flow the drum pressure decreases. Due to decrease in the pressure there is a temporary rise in the drum level. This is called as swelling effect. The shrinking effect is opposite to the swelling effect. To avoid these problems this paper suggests the method of pressure temperature compensating method.