NGP Belleville Spring Washers NGP's Live-load arrangements are designed to provide a sufficient gland load should in-service consolidation of the packing set occur. Belleville washers are manufactured from deburred, high tensile, grade 17-7 pH stainless steel. NGP 193 B-7 Gland Studs Replacement of the existing gland studs may be necessary to allow installation of the Belleville spring pack. NGP stocks both replacement eyebolts and continuous thread in certified 193 B-7. Nuclear Graphite Products (NGP) Main Page NGP 524 Graphitic Yarn Page NGP 6300J Flexible Graphite Seal Rings Page NGP Belleville Spring Washers Page NGP 193 B-7 Gland Studs Page NGP Style 6350 Graphite Lubrication Page NGP 6000 Composite End Rings Page NGP 5005 Graphite Spacer Bushings Page