1, push-type mechanical seal and non-push-type mechanical seal

Push-type mechanical seal means the seal along the shaft or sleeve auxiliary machinery to compensate by pushing the seal of the mechanical seal, usually refers to the compression spring mechanical seal.

Non-push for the auxiliary seal mechanical seal mechanical seal fixed to the shaft, usually bellows mechanical seal.

Push-type mechanical seal and non-push-type mechanical seal feature comparison table below.

Table push-type mechanical seal and non-push-type mechanical seal characteristics

2, balanced and unbalanced mechanical seal mechanical seal

Mechanical seal pressure in the sealed chamber in the ring to form a closure force, end of the film formed between the opening force. Load factor K> 1, sealing a non-balanced mechanical seal. General non-balanced mechanical seal can only be used for low pressure. When the pressure is greater than a certain limit, the sealing surface between the liquid will be squeezed out. Loss of liquid in the role of lubrication and high loads, the mechanical seal will soon damage the seal faces. Unbalanced mechanical seal can not balance the role of the liquid on the face, end with the fluid pressure than the pressure rise and rise.

Load factor K <1, closed for the balance of mechanical seal. Balanced mechanical seal shaft seal built-in steps to move within the radial seal face extension but does not reduce the width of the sealing surface. Seal opening force change, but a larger area of ​​ring exposed in the liquid, therefore, closing balance of power is a considerable part. Balanced mechanical seal seal exterior force balance method except the opposite direction, the other with the same built-in mechanical seals. In this case, to increase the hydraulic closing force of the share in order to offset the mechanical seal between the film's opening force. Balanced mechanical seal can be part of the balance between the role of the liquid on the face, end with the fluid pressure than the pressure rise and rise slowly. General non-balanced mechanical seal can only be used for low pressure, but the poor lubrication, low boiling point, easily vaporized medium and high speed conditions, even at low pressure, it should be used balanced mechanical seal. Because for non-balanced mechanical seals, mechanical seal chamber when the pressure rises, the liquid film between the seal faces will be out so quickly mechanical seal sealing surface damaged. Balanced mechanical seal can be used for all kinds of pressure situations.