NAC445A.6704. Pumping facilities: Seal water.

     1. A supplier of water shall ensure that mechanical seals and packing receive clean seal water, from a volute or an external source, for cooling and flushing. The seal water must not be of a lesser sanitary quality than that of the water being pumped.

     2. Where potable water is used as seal water and the water being pumped is of lesser sanitary quality, the line for the delivery of the seal water to the stuffing box must have a reduced pressure principle assembly or air gap.

     3. Where seal water is obtained from an external source, the line for the delivery of the seal water must be equipped with a pressure gauge at the stuffing box. The pressure of the seal water must be not less than 10 psi nor more than 15 psi higher than the pressure of the stuffing box and cause the water to flow from the stuffing box into the volute. Seal water must be obtained from an external source when the suction lift is such that there could be difficulty in priming as a result of leakage through the stuffing box.

     4. A supplier of water shall provide collection piping, which discharges into a drain, to accommodate any leakage from a stuffing box.

     (Added to NAC by Bd. of Health, eff. 2-20-97)