cold water enter the pressure chamber via side inlets 352 353 the outer housing 301 has a barrier 350 separating its lower and upper parts the upper valve housing 345 is seated against the lower surface of the barrier 350 the top part of the outer housing 301 is attached to the spout 371 and any water flowing into the top part passes through and out of the spout 371 the barrier 350 contains a series of holes 354 fig1 b through which the hot cold water mixture may pass when the valve is in an open position the barrier 350 also contains a separate central channel 398 which runs in a horizontal direction and connects has a separate central outlet 357 to the spout 371 filtered water may flow through this channel 398 by passing the valve system and exiting into the spout 371 the outer housing 301 has a series of circumferential grooves 397 around its outer surface which can each accommodate an o ring in order to seal the outer housing 301 against the inside of the faucet assembly 380 faucets delivering hot cold and filtered water are well known and described fro example in ep a 501989 0047 fig1 shows an underneath view of the faucet assembly the faucet assembly has three inlet pipes u2014 a hot water inlet 381 a cold water inlet 382 and a filtered water inlet 383 each inlet has a control valve 360 361 362 associated with it to control the flow of water the faucet assembly also has an outlet pipe 84 running through it this outlet leads to the spray when the spray is opened hot and cold water which have been mixed together in the valve assembly are diverted to this outlet 384.