I live near Ayutthaya and I'm trying to buy a 4" PVC backflow preventer. Has anyone seen one in their travels?

Try one of the bigger shops selling water well piping, etc. Ask for a 4 inch check valve

Thanks slapout. Appreciate that very much

The Global house in Udon has a huge selection of PVC valves, etc. I would think near Bangkok they would have an even bigger selection.

I'd put two of those in a line about 6" apart. The PVC ones aren't all that great.

This is my idea of a backflow/backpressure preventer and they aren't cheap but they work.

I'd put two of those in a line about 6" apart. The PVC ones aren't all that great.

This is my idea of a backflow/backpressure preventer and they aren't cheap but they work.

back.jpg

This is a real backflow preventer which is just a very fancy check valve. If you want to protect your drinking water supply this is the way to go but only one is needed with a by-pass. Do your reading and learn the preventive maintanence sch. very important that they are checked on a regular basis the set up to check them properly is very expensive.. This set up for home use would be a bit of overkill there are smaller units that can be installed on home supply