What is the basic requirement on the hot water boiler system?

a) Boiler hot water system design should meet the requirements of Code For Design of Boiler Plant GB50041.

b) Steam collecting device should be installed in the highest position of hot water system and the position where is easy to collect steam. Reliable constant pressure measures and circulating water expansion device should also be set to ensure that pressure in system is not lower than the corresponding saturation pressure of outlet water temperature plus 20 °C so as to avoid boiler water evaporation.

c) Constant pressure measures of low temperature hot water supply system can be realized by the expansion tank that installed in the highest position of system. In the high temperature hot water heating system, due to the high requirements of the stability of system water volume and operation, nitrogen constant tank is commonly used instead of expansion constant tank. Besides using expansion water tank and nitrogen constant tank, measures like constant pressure for automatic make-up water pump should be taken into consideration.

d) Steam collecting device should be installed in the highest position of system and the place where is easy to collect steam. Automatic water supply device shall be installed in the system and manual water supply device shall be installed at the place easy for operation.

e) There should be at least two water circulating pumps in forced circulation hot water system. When one of them stops running, total water flow of others shall meet the requirements of the largest circulation water volume.

f) Install by-pass pipe with check valve between front and rear pipeline of water circulating pump or adopt other measures to prevent water hammer when pump stops suddenly.

g) Dirt separator shall be installed at return water mains of system and dirt separator shall be installed at the place easy for operation to facilitate regular cleaning.

h) Boiler water quality shall be in accordance with Water Quality for Industrial Boilers GB1576.