Internally - some years ago - I installed an IMI pressure reducer valve like BES 9434 http://www.bes.co.uk/products/110.asp . This works very nicely - when it works (which is most of the time)!
The problem is that on occasions it does not completely shut off and the water pressure can creep up....stopping at a pressure that is too high and occasionally not stopping until it equalises with the supply. This can be alarming! (BTW this is my second valve of the type. They do have an integral grot-trap).
I am contemplating putting in an alternative valve and have found a Honeywell unit like this: http://tinyurl.com/yf5o52z
Does anybody have any experience or opinions on the best/most reliable pressure reducer valves? If so I'd appreciate your wisdom!
ps I AM in dialogue with the Water supplier about this. It would be great for them to reduce the pressure at source but but progress is "glacial".