Hi hope you can help... I have recently had a new torbeck valve fitted in my toilet and ever since this the toilet bangs when the valve shuts of on the toilet.. I have had a water hammer arrester fitted, also the valve has been checked on the stop cock.. that is OK... so I had the pressure reducing comb (for high pressure) taken out of my torbeck now I get a bang when it flushes and one when it shuts off, also all my pipes have been checked and are all secure... I noticed when I had my old torbeck removed it had two washers behind the blue retaning nut,. also why can you buy two types of torbecks one with a metal pin which holds the black shut off washer in place the other one has a black shut off washer with a small plastic pin in it which locates in a hole in the flush stork... would it help by putting the low pressure comb in instead of the one for high pressure, because the toilet without one in sounds like a jet wash when filling up,. please I need help before I put a sledge hammer through my toilet.:(