Steam Boiler Water Hardness

For boiler water the conductivity increases at the rate of approximately 2 of the value at 25 c for every 1 c increase in temperature.

Steam boiler water hardness. Phosphates are used to react with calcium hardness in the boiler water. Non volatile toc total organic carbon oily matter. Total silica 150 ppm maximum. Colormetry hardness detector prevent water hardness damage to your boiler with miura s colormetry hardness detection system.

Most boiler systems have sodium zeolite softened or demineralized makeup water. Total alkalinity 600 ppm maximum. It is desirable to keep the concentration of phosphates in the water to 30 50 ppm in order for complete reaction of the phosphates with the calcium hardness entering the. An increase in temperature results in an increase in electrical conductivity.

Broken down by feed water and boiler water and then by firetube. In order for this reaction to take place it is important to maintain a ph at a minimum value of 9 50. The concentration of minerals in the water is referred to as the water hardness. However boiler water is deliberately softened to prevent scale formation and this gives it a propensity to foam.

A boiler water sample has an unneutralised conductivity of 5 000 μs cm at 25 c. Hardness hard water does not foam. Feedwater hardness usually ranges from 0 01 to 2 0 ppm but even water of this purity does not provide deposit free operation. Total hardness 1 ppm maximum.

Colloidal substances contamination of boiler water with a colloid in suspension for example. Milk causes violent foaming. The quality of feedwater required is dependent on boiler operating pressure design heat transfer rates and steam use. Colloidal particles are less than 0 000 1 mm in diameter and.

Feed water boiler water characteristics as per is 10392 1982 1 feed water parameters upto 20 kg cm2 21 kg cm2 to 39 kg cm2 40 kg cm2 to 59 kg cm2 unit total hardness 10 1 0 0 5 ppm as caco 3 ph value 8 5 9 5 8 5 9 5 8 5 9 5 dissolved oxygen. Feed water purity requirements therefore can vary widely. A low pressure fire tube boiler can usually tolerate high feed water hardness with proper treatment while virtually all impurities must be removed from water used in some modern high pressure boilers. General guidelines to prevent corrosion and scaling in low pressure boilers are as follows.

This value will limit the silica content of the steam to 0 25 ppm as a function of selective. Water treatment recommendations vary depending on the operating pressure of the boiler the application steam or hot water and other parameters.