supply of supply of following items for modification in pfs & eppfs system in lhb coaches.supply of following items for modification in pfs & eppfs system in lhb coaches.,supply of following items for modification in pfs & eppfs system in lhb coaches. item i. pneumatic non return valve (nrv) size 1/4 inch both sid e female threaded. make- spac, cemcon, imi norgren or similar (material used for pfs in coaches) [ warranty period: 30 months after the date of deliver y ] ] , item ii. hex nipple size 1/4 inch suitable for pneumatic connection and working pressure of 08 kg/cm2 make- spac, cemcon, imi norgren or si milar (item use for modification in epfs in lhb coaches) [ warranty period: 30 months after the date of delivery ] ]