Two-handle faucets are most often found in the bathroom, but you see them in some kitchens. Two-handle faucets use three types of mechanisms. The first two are the same as two of the mechanisms used in a single-handle faucet: cartridge and ceramic disc. The third type is a compression (or reverse-compression) mechanism. Compression faucets are the simplest type, using rubber washers that get compressed against one another to seal the valve. They do tend to wear out faster than other faucet types, but are also least expensive to repair.
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.
If you have a major fix in your home, it’s important to shop around for a plumber to do the work. At least three bids will help you determine the range of the project, so you can weigh the pros and cons of price and the reputation of the plumbers. Get references and contact them. Also, a good plumber isn’t likely to nickel and dime you. For the smaller jobs, check out these 11 plumbing tricks.