Questions on Caleffi Zone Valve Specs That Will Serve as a Check Valve for a Hot Water Recirc System

I installed a recirc pump with a pex return line and I'm getting ghost flow which is wasteful and bugs me. Because my piping is mostly vertical, adding swing check valve is undesirable and I understand they are not robust with potable water. Instead I tried piping heat traps with 18 inches of drop.

The heat traps worked great after the water heater was restarted after working on the pipes, and leaving the pump off made the ghost flow insignificant even with 130 degree water the tank. But running the recirc pump for three or four minutes, cause continuous ghost flow unless I close a ball valve between the pump outlet and the water heater inlet.

In December 2016, there was a good thread on hot water recirc (titled: "Aynyone try?") where Mark Eatherton said:

"If a person wanted to make this gravity system as efficient as possible, you could incorporate a zone valve (rated for potable water applications) and set a timer that would open the ZV an hour before the earliest hot water use then close it until the next high use period occurs."

Using a zone valve seems like a great suggestion for my system with a pump that will be indirectly actuated by a momentary switch (24v), when hot water is desired.

Actually, the switch will:
- Start a timer that closes a NO (normally-open) switch in a 24V circuit that directly opens the Caleffi zone valve,
- the end switch of the ZV will turn the pump on when the switch gets to 50% open where the switch closes,
- the timer will cut power to the NO switch, thereby causing the zone valve to close, causing the end switch to open, thereby cutting 120v power to the pump.

The timer recommended by an electrical engineer friend is here:
https://www.automationdirect.com/adc/Shopping/Catalog/Process_Control_-a-_Measurement/Timer_Relays_-z-_Counters_-z-_Tachometers/Fuji_Electric_Timer_Relays_1-z-16_DIN_(MS_Series)/MS4SM-CE-ADC

We're almost to the questions. The zone valve I picked is the Caleffi Z451517 with the following specs:
- Actuator: Z151000 24 V AC
- Body: Z200517
- 2-way
- Normally closed
- 3/4" FNPT ports
- 7.5 CV
- potable water rated

- Low lead <0.25% lead brass body: 1st Question: Is this body really low lead? The Caleffi 2-WAY
ZONE VALVES Z-one Series Z200517 brochure says "Optional lead-free brass body" but I can't find specs that indicate which bodies are and are-not low lead.

- End switch: I'm pretty sure that the 24V actuator only comes with an end switch rated for 24V circuits. This will require a 24V relay that to open and close the 120V pump circuit. But it can't hurt to ask: Is this end switch rated for my Grundfos SS recirc pump which is 120V, 0.22 amps, 25 watts, 1/16 hp?

The zone valve will be installed between the pump outlet and the water heater inlet to stop the ghost flow I'm getting. The pex return line goes to the inlet of the pump.

The timer will be set for 4 minutes because it takes between three and four minutes to get the return T to 112 degrees in the upstairs bathroom. The water heater is on the south side of the basement very close to the 1st floor kitchen sink. The first and second floor bathrooms have faucets inches from the north wall.

To summarize, I have 3 questions:
- Is the valve body I spec'd (Z200517) low lead?
- Is the end switch rated for 120V, 0.22 amps,
- If a relay is required to control the 120V pump circuit, recommendations for a relay will be very helpful.

Thanks for following and any answers/recommendations,
Pidg