supply of non return nr valve 50 mm dia as per specification spec no mr elect 50mm nr w arranty period 12 months after the date of delivery supply of non return nr valve 50 mm dia as per specification spec no mr elect 50mm nr w arranty period 12 months after the date of delivery supply of sluice valve 50 mm dia as per specification spec no mr elect 50mm sluice warranty period 12 months after the date of delivery supply of non return nr valve 50 mm dia as per