2.1 General

• Valves and sea chests are to be easily accessible and permanently marked. Valves not easily accessible are in addition to be fitted with remote control.
• Shell valves are to be manufactured from non-heat sensitive materials 
• Normally bronze or other approved material
• Grey cast iron is not acceptable.

Shell and tube heat exchanger

Tube type cooler .cooler .heat exchanger

.tube cooler

Cooler article: https://marineengineeringonline.com/tag/l-o-cooler-leakage/

How many tube can be plugged: 10% tube can be plugged