Frost and ice on gas feed lines between chlorinators MOST likely indicates:

• A. Blockage in line
• B. Feed rate too high
• C. Diaphragm failure
• D. Malfunction of pressure reduction valve

Answer: (B)

Frost or ice on gas feed lines signals that chlorine gas is cooling as it expands when moving from high-pressure supply to the lower-pressure chlorination system. If the feed rate is too high, more gas passes through the regulator than the system can handle smoothly, causing greater expansion and a strong cooling effect. That cooling freezes moisture in the surrounding air on the line, producing frost. A blockage would tend to cause pressure buildup and heating at spots rather than cooling, and diaphragm or pressure-reduction valve issues would create flow problems or leaks rather than the characteristic frost. So frost between chlorinators is best explained by the feed rate being too high.