Types of solder & Backflow ?

[fred1949]

Question 1 is about solder I have bought. The old solder was labeled Sn95% & Sb 5%. The new solder I just bought was the same brand but there is no percentage on it. They both say lead free, I guess that is the important thing.

Question 2 is about whether or not I have to have a backflow on my outside faucet. The reason I am asking is I am changing the no-frost to a 1/4 turn hose bib. The no frost is shot & it is noisy. The 1/4 turn is in my opion a perfect replacement except not having the anti-backflow on it. I know why they use anti-backflow. It is to prevent contaminent from getting in your water supply. Please advise.

Thank you,
Fred

[LazyPup]

There are a number of different allow compositions that will meet ASTM (American Society of Testing & Materials) specification as listed in ASTM B-32 for soldering copper tubing.

Some solders will list the actual allow content such as the Sn95% & Sb 5% or the manufacturer may simply label there product as "Lead Free". In either case the labelling must state that the product is certified for use under the ASTM B-32 standard.

When copper pipe is run under a slab or structure we are required to use wrought copper fittings and all joints must be brazed. Solder joints are not permitted under a slab.

"Copper joints under concrete slab within a structure require brazed wrought-copper fittings" REF: International Residential Code 2904.14 & uniform Plumbing Code 609.3.2

I have cut and pasted the following information taken directly from the Copper Developement Assoc. website, and I have included their web address. You will find many other interesting facts regarding the use of copper pipe, fittings and methods of installation on their website.



CDA (Copper Developement Assoc.
Solders & Fluxes
Soldered joints depend on capillary action, which draws free-flowing molten solder into the gap between the fitting and the tube. Capillary action is most effective when the gap between surfaces to be joined is 0.002 to 0.005 in. To ensure that satisfactory joints are made, the tube’s cut ends must be deburred followed by mechanical abrasion to remove any surface film or soil prior to application of the flux.
Fluxes used for soldering copper tube and fittings should meet the requirements of ASTM B813, Specification for Liquid and Paste Fluxes for Soldering Applications of Copper and Copper Alloy Tube. Solders for joining copper tube systems contained in ASTM B32, Specification for Solder Metal, include 50-50 tin-lead, 95-5 tin-antimony, and a variety of lead-free alloys of approximately 95% tin combined with copper, nickel, silver, zinc, antimony, bismuth or selenium. Only lead-free solders are allowed for potable water systems.
Brazing Alloys & Fluxes
Strong, leak-tight connections for copper tube may be made by brazing with filler metals that melt at temperatures in the range of 1100 to 1500°F (593.3 to 815.6°C). Brazing filler metals suitable for joining copper tube are of two classes: The first class contains 30 to 60% silver (the BAg series) and the second class are the copper alloys that contain phosphorus (the BCuP series). The two classes differ in their melting, fluxing and flow characteristics, but both provide the necessary strength with standard fittings. Flux may be omitted when joining copper tube to wrought copper fittings with alloys of the BCuP series as they are self-fluxing. Fluxes are required for joining to cast copper alloy fittings or when using BAg-series filler metals.
The fluxes used for brazing copper tube should meet AWS (American Welding Society) Standard A5.31 and be of classifications FB3-A or FB3-C.

Ref: COPPER DEVELOPMENT ASSOC. website,

http://www.copper.org/applications/plumbing/Overview/cu_alloy_tube_pipe.htm#sldrflx

Under the current code requirements ALL faucetts that are equiped with a hose attachment are required to have either a Backflow preventer or vacuum breaker. This not only includes hose bibbs but it also includes kitchen sink pull out sprayers, bath tub hand shower lines, and utility sinks if they are fitted with a short length of hose for filling mop buckets etc. A shower stall hand sprayer is not required a backflow preventer or vacuum breaker if the maximum downward lenght of the hand shower head remains a minimum of 2" above the flood level rim of the shower stall threshold.

A valve with a drain is required on all hose faucetts which are subject to freezing.

In climates that are only subject to the occassional freeze the local codes may permit the use of "Frost proof" hydrant type silcocks however it must be remembered that "Frost Proof" is not "Freeze Proof". Some jurisdictions permit the use of frost proof hydrants providing the valving mechanism remains inside the structure wall. In the case you may use the common 6" or 8" frost proof silcock.

In some colder climates the code requires the valve to be a minimum of 24" inside the structure and in this case they do make a 24" frost proof silcock. In my jurisdiction we are required to have a "Line Stop & Waste Valve" at least 36" inside the structure.

Personally I prefer the stop & Waste valve inside the structure simply for economic reasons. A stop & waste line stop is about $5 and a common hose bibb is another $5 for a combined total of $10 as opposed to $12 to $25 for the frostproof hydrants, and in the unfortunate event that you do have an outside faucett freeze and break you can simply replace just the faucett for $5 instead of replacing the complete frostproof hydrant.