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What type of bronze is used for modern works of art?

Bronze has been used for centuries to create statues, and is still the first choice for modern, striking works of art. The most widely-used alloys for such objects are leaded gunmetals, such as CC492K and CC491K.
I am trying to identify the brass Hpb59-1. It is proposed to use this brass in the cast condition for valves used in fire protection systems in buildings.

This is a Chinese Specification composition 57-60 copper, 0.8-1.9% lead, balance zinc. It is a leaded Muntz Metal. A more suitable alloy for this application would be the gunmetal LG2 (CC491K) 85%copper, 5% tin, 5% zinc, 5% lead. It has better corrosion resistance and is easily cast.
I am using a leaded gunmetal casting which is machined and then crimped onto a copper pipe. I have had a number of failures due to leakage. Can you explain this?

Leaded Gunmetal is a cast alloy which is not designed to be cold worked. Crimping involves extreme deformation which will not usually be tolerated by the gunmetal without cracking. However, castings do not have a uniform structure and in the areas free from lead and possibly a smaller grain size some ductility is present. This will account for some of the castings surviving the crimping without cracking.
I have been asked to produce 22 valves in gunmetal from a drawing which originates from 1958. The company has been taken over and the patterns and casting drawings lost. Due to the small quantity that will have to be made from bar, what should I use?

Suggest that you use continuously cast CC491K (LG2) bar or a wrought free-machining phosphor bronze.
What material is recommended for underground pipe fittings?

Gunmetal or dezincification resistant brass.