Restrictions on the use of O-rings
1.0 Restrictions on the use of O-rings, O-rings, O-rings, O-rings
Static sealing
In a true static seal, the matching gland components do not undergo relative motion (except for small thermal expansion or separation caused by fluid pressure), which is the opposite of a seal where one of the gland components moves relative to another component. Examples of static sealing include sealing under bolt heads or rivets, sealing at pipeline or pipeline connections, sealing under covers, plugs, or similar devices, or usually equivalent to flat washers. Figures 1-8 illustrate a typical static seal.
Reciprocating seals
In reciprocating seals, there is relative reciprocating motion (along the axis) between the internal and external components. This movement often slides back and forth or rolls the O-ring or sealing surface at the O-ring with reciprocating motion. Examples of reciprocating seals are the piston in the cylinder, the plunger entering the chamber, and the hydraulic actuator securing the piston rod. Figures 1-9 illustrate a typical reciprocating seal.
Oscillating seal
In a swinging seal, the internal or external components of the sealing component move in an arc (around the axis of the axis) relative to another component. This movement tends to cause one or another component to rotate relative to the O-ring. When the movement arc exceeds 360 °, such as multiple rotations of the valve handle, the return arc in the opposite direction will distinguish the swinging seal from the rotating seal. Except for very special cases, any longitudinal movement (caused by the spiral) that belongs to the swing seal is not important. An example of a swinging seal is an O-ring seal used for the valve stem of a faucet
Rotating seal
In a rotating seal, the internal or external components of the sealing element rotate only in one direction (around the axis). This applies when the rotation is reversible, but it is not allowed to start and stop after a brief motion arc, which is classified as a swing seal. Examples of rotating seals include sealing the motor or engine shaft, or fixing the wheels on the shaft.
Seat seal
In the valve seat seal, the O-ring is used as one of the contact components to close the flow channel. Compared to the previously defined sealing conditions, the motion of closing the channel mechanically twists the O-ring to form a seal. Compared to non impact closure, a subcategory is impact closure. Examples of seat seals include O-rings as “washers” on the surface of spiral threaded valves, seals on floating check valve cones, and seals on the end of electromagnetic plungers.
Pneumatic seals
Pneumatic seals can be any type of O-ring seal described earlier, but are assigned different classifications due to the use of gas or steam instead of liquid. This has a significant impact on the lubrication of the O-ring, thereby affecting all moving (or dynamic) sealing devices. Another point is that pneumatic seals may be affected by the increase in gas temperature during compression. Please note that the seal should be defined as “pneumatic rotary” or similar for complete identification
Vacuum sealing