Figure 1-29.General laboratory equipment.
Test for Hardness
The following caution applies to each
test that is discussed: IF THE TESTING
PROCEDURES OF THE EQUIPMENT
AND/OR REAGENT SUPPLIER
DIFFERS FROM THAT PRESCRIBED
IN THIS TEXT, THE SUPPLIERS
PROCEDURE SHOULD BE USED.
Boilers operating at pressures of 15 psi and less are
normally used for space heating and hot-water
generation. Practically all the condensate is returned to
the plant. Only a small amount of makeup is required,
and secondary feedwater treatment usually is sufficient.
When appreciable quantities of steam are used in process
work and not returned as condensate to the plant, the
problem of scaling and corrosion arises, and more