Centring guide for the quartz sleeve wiper system of a Trojan ultraviolet reactor. It holds the wiper concentric to the sleeve so contact pressure is even the whole way round. A wiper running off centre cleans one side of the sleeve and leaves a band of fouling on the other, which the intensity sensor reads as a low-transmittance fault even though the lamp and the drive are both working. Trojan part 794437. Contact us if you are unsure whether this part fits your UV system.