The helical spring design is intended for static applications due to the high unit load. It can be used in very slow or infrequent dynamic conditions when friction and wear are secondary concerns to positive sealing. The H Series spring produces evenly distributed load across each individual band, with very small gaps between the coils, This tight spacing provides near continuous load, reducing potential leak paths. This combined with the high unit load makes the H Series well suited for vacuum and cryogenic applications or when pressure is too low to energize the seal. The load provided by the H Series spring is directly through it’s center line. The lip design of the seal is a full radius at the sealing interface, providing maximum load to the contact points to effect a tight seal. The spring is welded at the ends and is retained in the seal by parallel side cuts in the spring cavity. When the seal is compressed into the hardware, the spring cavity is designed to allow the axial growth of the spring. The relatively small deflection range of the H Series spring prevents it from being used in applications having wide gland tolerances, eccentricity or misalignment. V or C Series seals should be considered for these conditions.