Shuddering pipes

Hi all,

Could someone tell me why when I turn my outside tap on there is a really bad shuddering and if I dont either open the tap up more or close a bit the noise sounds like everything is just going break.

It only occurs on the garden tap, and it seems to occur at different turning of the actual tap i.e. sometimes I can turn is very slightly and it will make a noise and this would require me to open it up more and eventually the shuddering will stop or another time I could open a lot in one turn and it requires me close it slightly to stop the shuddering.

Anyone know what could be causing this since this is the only tap that does this I was wondering its the tap itself?

Thanks

you requie a new tap washer it has detached from its seat

Thanks much appreciated

You need a Corgi approved plumber to ascertain the prescence of a double check valve and to test the efficacy therof and to connect the new tap using potable water only jointing compound and a frostproofing kit and to sign of parts B-oLC Kand S of two shags regulations a