Wall thickness does not affect pipe or tubing size. 1/2" L copper has the same outer diameter as 1/2" K or M copper. The same applies to pipe schedules. As a result, a slight increase in pressure losses is realized due to a decrease in flowpath as wall thickness is increased. In other words, 1 foot of 1/2" L copper has slightly less volume than 1 foot of 1/2 M copper.
General employment within the construction sector is sensitive to changes in the economy. But job growth for plumbers is projected to be faster than the average for all jobs. New buildings and residences are being built to comply with stricter water efficiency standards and companies housed in older structures are hoping to retrofit to use more energy-efficient systems, so opportunities are in abundance. According to the Bureau of Labor Statistics, there should be a hiring spurt of 16 percent for plumbers by the year 2026, which translates to about 75,800 new jobs.