A thermostatic bar mixer valve is an exposed shower valve that spans two fixed wall inlets at a standardised centre-to-centre spacing (conventionally 150 mm), interchangeability being guaranteed by that dimensional standard together with a fixed supply convention — hot on the left, cold on the right — because the thermostatic cartridge references the cold feed to modulate blend temperature independently of the separate flow control. The joint at each inlet is a compressible-washer face seal: a felt or elastomeric washer between the union nut and the wall-fitting shoulder seals on light preload, distinguishing it from the metal-deforming compression joint that secures the wall bracket to the copper supply pipe behind it. This belongs to sanitary and domestic hot-water services within plumbing, and illustrates how modular, standards-based interfaces let a wearing component be replaced without disturbing the fixed pipework it serves.
A thermostatic bar mixer valve is an exposed shower valve that spans two fixed wall inlets at a standardised centre-to-centre spacing (conventionally 150 mm), interchangeability being guaranteed by t…