Natural gas HW heater - replacement help

I'm planning to replace my 12-year old natural gas 40 gallon hot water heater (see attached photos) with a new Whirlpool nat gas 50 gallon tank. I've replaced an electric hot water tank before, but never done much with gas. Given that, plus the fact that my home is almost 90 years old, I have a few questions, hoping someone can help.

1. In the 4th photo (IMG3862) you can see the shutoff on my black iron pipe natural gas line running to the water heater. It looks to me like an old water line shutoff rather than the nice new gas 1/4 turn shutoffs. Should I mess with replacing it? I am a little worried about trusting it to actually "shut off" while I'm working on the line below connecting to the tank.

2. In the 5th photo (IMG3863) it shows where the "L" of the above mentioned black iron gas line comes down (full view in 1st photo - IMG3859). This is maybe the most curious part for me. Is the new tank going to have the nat gas hookup in almost the exact same spot as this tank? Or will I be having to make significant adjustments messing with the height and length of the black iron gas line trying to get it to line up with my new tank's hookup? Is a nat gas flex line hookup acceptable to use (I've seen them on stove/oven hookups, but never a water heater).

3. For the water connections on top of the tank (2nd photo - IMG3860), should I stick with the copper lines or can I replace those with flex lines? Obviously I would need to install a new shutoff as well.

I greatly appreciate input anyone can provide on any of those points. I'd really like to save some $$ and tackle this myself, but I don't want be taking risks with my home by improperly connecting new gas lines.

Thanks!!

 

I don't think that globe valve was ever allowable for that usage, I would replace it with an AGA (American Gas Association) branded quarter-turn shut-off valve.

Whether or not you can use flexible connectors on either the water or gas connections is spelled out in your LOCAL plumbing or mechanical codes. Some jurisdictions require hard piping and others prohibit hard piping. You may also need to provide seismic (earthquake) restraints and if so the code(s) will give the details.

Here is some information for my area. Scroll down to item #07. for the pdf concerning water heaters. Your codes may be different. https://mybuildingpermit.com/Pages/c...ip-sheets.aspx

 

I am not commenting on the installation particulars, but just on your choice of a new water heater. In case you aren't aware, Whirlpool doesn't make water heaters. The Whirlpool branded water heaters are manufactured by American Water Heater under license from Whirlpool. I used to think a lot of the American units, they gave really great bang for the buck and lasted a long time, but American seemed to have lost their way when FVIR technology was mandated. Take a look at some comments:

Top 1,652 Complaints and Reviews about Whirlpool Water Heaters

I would recommend you buy an AO Smith or Bradford-White water heater.

 

Thanks guys - with regards to brands, what about Rheem? Better than Whirlpool?

 

Probably, but I cannot definitively say that as a fact. Rheem/Ruud water heaters used to be good solid performers, but I really have no knowledge of their performance with the newer FVIR technology. Home Depot has been selling them for at least 15 years, but in the last two years they have dropped the GE label for the Rheem label. That to me was interesting, but I have no idea why they did that.

 

I have a Rheem I bought at Home Depot two months shy of two years ago this coming Saturday. Haven't had a single problem. My previous heater, from Sears, lasted for fifteen years and two months according to the install date written on it.