The seal contains the secondary seal, the o ring. The face materials and elastomers can be varied as per the requirement of the application. The conical helical springs transmit the torque. The seals depend on the direction of the rotation. The conical helical spring can be fitted easily by pushing on the shaft and twisting as the spring winding. So, the spring diameter enlarges easily to make it easy to fit. One can judge the direction of the rotation from the drive end of the shaft.The clockwise rotating shaft requires a right-handed spring and the anti-clockwise rotating shaft requires a left-handed spring.The conical single spring unbalanced seals are used in the central heating systems in circulation pumps. Its also used in chemical process pumps, sewage and submersible pumps, and chemical process pumps.Seal Characteristics Inside Mounted Single Acting unbalanced Dependent On the Direction Of RotationApplication Circulation Pumps For Central Heating. Water Pumps Sewage & Submersible Pumps Chemical Process Pumps