Go to the sprinkler data sheet and look under finishes. Each manufacturer has footnotes. White Teflon seems to be the best. A more expensive alternative is stainless steel and you can always call the manufacturer.
I'd be more worried about the pipe, though.
The last time we provided a sprinkler system for a pool, we used stainless steel pipe and stainless steel heads. Expensive but effective.
(NFPA #13 220.127.116.11 and A.18.104.22.168)
I woudl also add that most manufacturers are now offering a version of Nickel PTFE (Teflon) finishes. Note that some corrosion-resistant finishes cover the frame and deflector, but not necessarily the other components. Victaulic's VC-250 is another good option that is my current favorite. Your manufacturer-of-choice's rep should be able to help. No matter which brand, Victaulic's Sprinkler Coating Data Sheet TB-901 has some good info on finish comparisons.
I just had lunch with the national viking rep and we discussed this very issue. We had be specifying PTFE for pool equipment areas and were told this was incorrect. PTFE apparently is not good for chlorine areas which contradicts Vikings earlier statements. The rep suggest that poly or wax is the best option. Stainless steel did not hold up well to chlorine in their long term test as well.
Thanks, that’s interesting info, Christopher. While it does not recommend which finish for what application, if you can find it, Viking’s “Sprinkler Corrosion Resistant Finishes” data sheet does a very good job of comparing the different finishes relative to each other, and which parts are actually coated. Poly for example generally only protects the frame and deflector, while other finishes protect the other components, the whole assembly, or even the waterway. While a designer/PM, I found it very valuable to build working relationships with the major reps. If you filter through their inherent biases, I have usually found them to be of high integrity and very helpful. They often buy lunch, too.
I just talked to a technical services rep at yet another sprinkler manufacturer, also recommended against PTEE and even stainless. Recommended educating the owner that the sprinkler may have to be replaced more frequently. But wow, maybe factory-dipped wax is still the best. Here is a related answer from NFPA in an NFPA 25 Q&A I Googled:
Any sprinkler found to be corroded must be replaced in accordance with Section 22.214.171.124.2. Anytime brass is exposed to constant moisture (particularly combined with chlorine), corrosion will result. Sprinklers exposed to these conditions, should be wax coated to protect the sprinkler from corrosion. Wax coated sprinklers are available from any sprinkler manufacturer. Wax is not permitted to be applied after the sprinkler leaves the manufacturer.
Explosion Protection & Prevention
Fire Detection And Alarm Systems
Flammable & Combustible LIquids
Information Sources For Analysis
Means Of Egress
Passive Building Systems
PE Prep Guide
PE Prep Series
PE Sample Problems
Smoke Management Systems
Special Hazard Systems
Types Of Analysis
UFC 3 600 01
Water Based Fire Suppression