A PVC gate valve is quite a complex valve compared to more simple valves, like a ball valve, but is fantastic for fine control of flow. The wheel at the top of the valve has about eight/eight-and-a-half turns from fully shut to fully open, which allows for very small movements in the internal workings of the valve. This gives you fine control of your flow.
When the gate valve is fully open it has a full-bore flow all the way through, much the same as a ball valve. If your valve is running and you've got it set at half, or even less, and you think there might be something blocking it, that blockage can often easily get cleared just by opening the valve fully, letting any debris past, and then resetting the valve to where you want.
There are no metal parts at all in the gate valves; everything is PVC and the seals are EPDM. This means there is nothing to rust or seize, and you'll get many years of really good service out of them.
The operating pressure of these valves depends on the size of valve – below is a table that illustrates the different pressure ratings in relation to valve size.
We would always recommend fitting gate valves with a union either side of them. This means if your valve is ever blocked or needs to be checked, you can easily and quickly unscrew the unions, take the valve out, and then put the valve, or a new valve, back into service. There are nuts on the top of the valve which undo, but removing the valve this way is a lengthy process. Therefore, we recommend the time-saving option of fitting a union on either side of the valve.
If you would like to watch a video explaining this a little more then you can visit our YouTube channel and watch the video!