"Where do you use compression versus flare?"
We prefer flare with soft tubing over 3/8"od in size and compression fittings on all hard copper and soft tubing 3/8"od and smaller. Don't use compression fittings on gas connections at all as most codes do
not allow it nor do we recommend it.
"Since these are brass fittings do they contain lead?"
Most of these fittings do contain a very small amount of lead. Consider that for many years copper fittings and pipe
were soldered together with 50% lead and now little lead may be used by law. Same with these brass fittings. There
is a small amount of lead in them. The more acidic the water, the more tends to leach out. Should you be concerned?
Some would argue that any amount is bad, and they would not use it for potable water. Others argue that plastics
will be the new "asbestos" of the future. We don't know, and we cannot recommend these fittings for potable water; but we
can say that we ourselves drink our own water from and through these fittings.
"I have standard 1/2" copper solder fittings, can I use 1/2" compression fittings in its place?"
Probably not. In the plumbing trade when we say 1/2" soldered fittings we mean fittings that use 1/2" nominal pipe (which means 5/8" outside diameter pipe). To figure what size pipe to use with "standard" solder (not compression like those above) plumbing fittings, you must add 1/8" to your measurements to know the o.d. (outside diameter) of the pipe. 1/2" nominal fittings use 5/8" od pipe; 3/4" fittings uses 7/8" pipe and so on.
It can all be confusing. The above compression fittings use the outside diameter of pipe, so a 1/2" compression fitting uses 1/2" outside diameter copper pipe. "Standard" plumbing terminology with copper solder fittings use "nominal" pipes but not so with compression fittings. That means a "standard" 1/2" soldered fitting uses the same pipe as 5/8" compression pipe.
For above compression fittings simply measure the outside diameter of the pipe and that is the size of the compression fitting that you should order. 1/2" outside pipe means you need to order 1/2" compression fittings.
"How will I know which size compression fittings to use for my copper tubing?"
You will need to measure the outside diameter of your copper tubing. Whatever the outside diameter of your copper tubing is will be the size of the compression fitting you will need. For instance, if the outside diameter of your copper tubing is 1/4" then the compression fitting will need to be 1/4". Compression fittings are not sized like copper sweat fittings.
"I have clear vinyl tubing, can I use these compression fittings with it?"
It really depends on the outside and the inside diameter of the clear vinyl tubing. When using plastic tubing, the "plastic sleeve" must be used and the "brass insert" must be used. The plastic sleeve is used to seal against the outside of the plastic tubing and the tapered end will seal into the compression fitting. Plastic sleeves are used because the brass compression sleeves can more easily cut into the plastic tubing, potentially causing a leak. The brass insert is used to keep the inside of the plastic tubing from collapsing as the compression fitting is tightened. The size of the plastic sleeve and the brass insert must be chosen according to the outside dimensions of the clear vinyl tubing to be used. The brass insert must be able to fit snugly inside the clear vinyl tubing and will generally work if the clear vinyl tubing has 1/16" wall thickness.
"What is the difference between 'nominal' dimensions and 'outside diameter (OD)' dimensions?"
Nominal is the term used to describe most pipe and fitting measurements in the plumbing industry. Nominal refers to the inside diameter measurement of the pipe. The actual inside pipe measurements will vary slightly due to the wall thickness of the pipe, so it is referred to as "nominal" meaning a small variance of size. The outside diameter (OD) dimensions refer to the actual outside diameter of the pipe. The outside diameter dimensions of pipe are a constant size which allow pipe fittings to be used with the same type of piping with multiple grades of wall thickness.
