What is the minimum required difference in size between a pipe and its sleeve?

The minimum required difference in size between a pipe and its sleeve is 1/2" greater. This specific measurement serves a critical purpose in ensuring that there is adequate space for movement and thermal expansion without compromising the integrity of the system.

When piping is installed, it is not unusual for the pipes to expand or contract due to temperature changes or other environmental factors. A 1/2" difference allows for this natural movement without placing excessive stress on the piping or sleeve. It also helps to prevent situations where the pipe could become stuck within the sleeve, which might lead to damage or potential failures in the system.

Having a sleeve that is 1/2" larger also allows for proper sealing during installation, which is essential for preventing leaks. If the difference were too small, it could lead to difficulties in installation, as well as operational issues later on. Thus, the specification of a 1/2" greater size is a standard that balances maintenance ease, safety, and effectiveness in plumbing and piping systems.