What the difference betwween part 1 and part 2 Ball cocks?

[rab250]

please tell

 

[Winston]

Part 2 has a non return valve to prevent backflow of water.

 

[jpm]

please tell

And one is made exclusively in Portsmouth

 

[helpsy]

Hi rab250
Part 1 = piston type(outlet below main body,requiring non return valve to be used to prevent backflow)

Part 2 = diaphragm type (outlet above main body)

 

[justlead1]

And some are made i Croydon

 

[bathroomboy]

Correct me if I am wrong but I have ever heard of a non return valve on a float valve, the air gap is the back flow preventer and with the overflow the level of water should never be able to reach the valve.

 

[Mushybees]

Correct me if I am wrong but I have ever heard of a non return valve on a float valve, the air gap is the back flow preventer and with the overflow the level of water should never be able to reach the valve.

Correct. There's no check valve in a part 2 float valve.