We have found that the pricing for bronze valves for small diameter threaded is high, and for general service (we use for steam and water) we have moved to a forged steel valve with stainless internals. These valves are rated at a MUCH higher pressure (800 psi vs 300) AND are less expensive. Many manufacturers make both the bronze and forged, we use Powell, but have used Vogt, Velan, etx.
Your question is a typical 'crossover' technical/commercial question of what is commercial available and cheapest/best on the market.
This question is always related to:
Logistics
-What is produced within cost accesible transport distance-
Market and application
- There is still for instance some producers that are producing low-priced bronze valves for common seawater/ship use; where for larger valaves or valves for higher pressures, requiring special castings or bar-stock, the bronze material could be replaced by other non-corrosive materials, or steel- /nodular iron if adequate.
I do not believe there is a single answer to your question without specifying application details.
As above, without further details, it's difficult to spec alternatives, but in general, the only alternatives we usually see for bronze is monel, and we only see that in the trim. Price is obviously a factor. I've never really seen duplex as an alternative to bronze.
Heather Smith
My interests: Alloy valves, duplex valves, super duplex valves, 6Moly valves, inconel valves, incoloy valves, alloy 20 valves and titanium valves.